A statistical analysis is internally validâ if:
A.
the regression R² > 0.05.
B.
the statistical inferences about causal effects are valid for the population studied.
C.
all tâ-statistics are greater than | 1.96 |
D.
the population isâ small, say less thanâ 2,000, and can be observed.

The probability of selecting two families, neither of which had their taxes prepared by H&R Block is (7/10) * (6/9) = 42/90, which simplifies to 7/15.

a. There are a total of 10 families. 7 had taxes prepared by a local professional, and 3 by H&R Block. This means 0 families prepared their own taxes. The probability of selecting a family that prepared their own taxes is 0/10 = 0.

b. Since no families prepared their own taxes, the probability of selecting two families, both of which prepared their own taxes is 0.

c. Similarly, the probability of selecting three families, all of which prepared their own taxes is 0.

d. If we want to select two families, neither of which had their taxes prepared by H&R Block, we are looking for families that had their taxes prepared by a local professional. There are 7 such families. The probability of selecting the first family is 7/10. After selecting the first family, there are now 9 families left, 6 of which had their taxes prepared by a local professional. The probability of selecting the second family is 6/9. Therefore, the probability of selecting two families, neither of which had their taxes prepared by H&R Block is (7/10) * (6/9) = 42/90, which simplifies to 7/15.

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1. The probability that the number picked is divisible by either 4 or 5 or both is 0.4. 2. The probability that the number picked is divisible by 4 and not 3 is 0.167.

1. Using the principle of inclusion-exclusion. There are 250 integers between 1 and 1000 that are divisible by 4, and 200 integers that are divisible by 5.

However, some integers are divisible by both 4 and 5 (i.e., by 20), and we have counted them twice. There are 50 integers in the range [1, 1000] that are divisible by 20.

So, the number of integers between 1 and 1000 that are divisible by either 4 or 5 or both is:

250 + 200 - 50 = 400

Therefore, the probability that the integer picked is divisible by either 4 or 5 or both is:

400/1000 = 0.4

2. Using the principle of inclusion-exclusion again, there are 250 integers between 1 and 1000 that are divisible by 4, and 333 integers that are not divisible by 3.

There are 250 integers in the range [1, 1000] that are divisible by 4, and 83 integers that are divisible by 12.

So, the number of integers between 1 and 1000 that are divisible by 4 but not 3 is:

250 - 83 = 167

Therefore, the probability that the integer picked is divisible by 4 and not 3 is:

167/1000 = 0.167

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Answer: 9x=45

Step-by-step explanation:

“product” means the result from multiplying two numbers, so if the product of the two numbers is 45, then the two numbers provided (9 and x) are being multiplied.  

If we were to solve for x, we could divide both sides by 9 to get 5.

Answer:

83

Step-by-step explanation:

78 + 4= 83

The length of the line segments m and n which are halves of the diagonals AC and BD in the parallelogram ABCD are 6 and 11 respectively.

A parallelogram is a quadrilateral, and the diagonals always bisect each other. However, diagonals only form right angles if the parallelogram is a rhombus or a square.

For the parallelogram ABCD; the lines AC and BD are its diagonals, and they both bisect each other, that is they cut each other to form two equal parts.

So AP and PC are equal halves of the line AC, while BP and PD are equal halves of the line BD

Therefore, since PC = 6 then m = 6, and for PD = 11, then n = 11 because they form diagonals of the parallelogram ABCD.

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1.39 is the median of the distribution

Creating a table:

X :___0 __ 1 __ 2 ___ 3 ____ 4 ___ 5 ___ 6

P(x):0.02_0.03_0.07, 0.12, 0.30_ 0.28_0.18.

The standard deviation = √(Var(x))

Var(x) = Σx²*p(x) - E(x)²

E(x) = ΣX*p(x)

E(x) = (0*0.02) + (1*0.03) + (2*0.07) + (3*0.12) + (4*0.30) + (5*0.28) + (6*0.18) = 4.21

Var(X) :

[tex]((0^2*0.02) + (1^2*0.03) + (2^2*0.07) + (3^2*0.12) + (4^2*0.30) + (5^2*0.28) + (6^2*0.18)) - 4.21^2[/tex]

19.67 - 17.7241

= 1.9459

Standard deviation = √(Var(X))

Standard deviation = √(1.9459)

Standard deviation = 1.3949551

= 1.39

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Full Question ;

Hannah has a chicken coop with 6 hens. Let X be the total number of eggs the hens lay on a randomly chosen day. The distribution for X is given in the table.

A 2-column table with 7 rows. Column 1 is labeled number of eggs with entries 0, 1, 2, 3, 4, 5, 6. Column 2 is labeled probability with entries 0.02, 0.03, 0.07, 0.12, 0.30, 0.28, 0.18.

What is the standard deviation of the distribution?

1.39

1.95

2.16

4.67

The probability of selecting blue marble and green marble is 1/13.

A probability is a number that reflects the chance or likelihood that a particular event will occur. The certainty of an event is 1 which is equivalent to 100%.

Probability = sample space/total outcome

total outcome = 13

The probability of picking blue in the first pick = 6/13

since there is no replacement, the total outcome for the second pick = 12

The probability of picking green in the second pick = 2/12 = 1/6

Therefore the probability of selecting blue and green marble = 6/13 × 1/6

= 1/13

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The area of each shaded sector of a circle with radius 6 units and measure of central angle 36 degrees is approximately equals to the 11.31 square units.

The area of a sector is defined as the space inside a section of the circle made by two radius and an arc. The area of a circular sector is written by the following formula [tex]Area = \frac{θ}{360°}\pi \: r^2[/tex], where, r represents the radius

See the above figure, we have a circle with radius of circle, r = 6 units

Measure of central angle, θ = 36°

Area of circle = πr²

Substitute all known values, so, Area = π× 6² = 36π

Using the formula for the area of a sector, Area of sector of circle with radius 6

[tex] = \frac{36°}{360°}π(6)²[/tex]

[tex]= \frac{1}{10} \times 36 × 3.14[/tex]

= 11.304 ~ 11.31

Hence, the required area of the shaded sector is approximately 11.31 square unit.

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Complete question:

The above figure complete the question.

Find the area of each shaded sector. Round to the hundredths place

Answer:

$78.7092

Step-by-step explanation:

He wants to buy a skateboard. The percentage value of the skateboard before any changes is 100%. So $73.56 = 100%. Now when you add a sales tax to it, the price will increase by 7% so it'll now be 107% right? You just have to find how much the 107% is equal to.

100% = 73.56

1% = 73.56÷100 = 0.7356

107 % = 0.7356 × 107 = 78.7092

Answer:

First, let's find the equation of the circle with a centre at (-4,5). the standard form of a circle is (x - h)^2 + (y - k)^2 = r^2, where (h,k) is the centre of the circle and r is the radius.

So, substituting the center point (-4,5) into the equation, we get:

(x - (-4))^2 + (y - 5)^2 = r^2

(x + 4)^2 + (y - 5)^2 = r^2

Now, let's find the slope of the line 2x + 3y = -19 by putting it into slope-intercept form:

2x + 3y = -19

3y = -2x - 19

y = (-2/3)x - (19/3)

The slope of this line is -2/3.

At a given location, the tangent to a circle is perpendicular to the radius. As a result, we must calculate the radius of the circle with centre (-4,5) that passes through the line's point of tangency (x,y).

The radius of the circle is equal to the length of the perpendicular line segment from the centre to the tangent line (-4,5). This perpendicular line segment will be denoted by the letter d.

We may use the formula for the distance between a point and a line to get d. The distance d between the point (x,y) and the line 2x + 3y = -19 is calculated as follows:

d = |2x + 3y + 19| / sqrt(2^2 + 3^2)

To be tangent to the circle, the radius should be equal to d. Let's call this radius r.

So, we have two equations:

(x + 4)^2 + (y - 5)^2 = r^2 (equation of circle)

d = |2x + 3y + 19| / sqrt(13) (equation of distance between point and line)

Substituting d = r into the second equation, we get:

r = |2x + 3y + 19| / sqrt(13)

We can now substitute this expression for r into the equation of the circle:

(x + 4)^2 + (y - 5)^2 = (|2x + 3y + 19| / sqrt(13))^2

Since the point of tangency lies on the line 2x + 3y = -19, we can substitute (-19 - 3y)/2 for x in the above equation and solve for y:

((-19 - 3y)/2 + 4)^2 + (y - 5)^2 = (|2((-19 - 3y)/2) + 3y + 19| / sqrt(13))^2

Simplifying and solving for y, we get:

y = -5 ± 2√13

Therefore, the two tangent points are (-19/2, -5 + 2√13) and (-19/2, -5 - 2√13).

The correct answer is option b.

To find the median, we need to first put the observations in order:

5, 7, 10, 10, 10, 14, 14, 15, 18, x

Since there are 10 observations, the median is the average of the 5th and 6th observations, which are both 10. Therefore, the median is 10.

To find the mode, we need to find the observation that appears most frequently. Here, both 10 and 14 appear three times each, so the data has two modes: 10 and 14.

To find the standard deviation, we need to first find the mean of the data. We know that the sum of the observations is:

5 + 7 + 10 + 10 + 10 + 14 + 14 + 15 + 18 + x

= 103 + x

Since we know that X = 11.6, we can substitute to get:

Sum of observations = 103 + 11.6 = 114.6

The mean is then:

Mean = (Sum of observations) / (Number of observations)

Mean = 114.6 / 10 = 11.46

To find the standard deviation, we need to calculate the deviation of each observation from the mean, square each deviation, find the average of the squared deviations, and then take the square root.

Deviation of 5 = 11.46 - 5 = 6.46

Deviation of 7 = 11.46 - 7 = 4.46

Deviation of 10 = 11.46 - 10 = 1.46

Deviation of 10 = 11.46 - 10 = 1.46

Deviation of 10 = 11.46 - 10 = 1.46

Deviation of 14 = 11.46 - 14 = -2.54

Deviation of 14 = 11.46 - 14 = -2.54

Deviation of 15 = 11.46 - 15 = -3.54

Deviation of 18 = 11.46 - 18 = -6.54

Deviation of x = 11.46 - x

To find the standard deviation, we need to find the average of the squared deviations.

Average of squared deviations = [(6.46)^2 + (4.46)^2 + (1.46)^2 + (1.46)^2 + (1.46)^2 + (-2.54)^2 + (-2.54)^2 + (-3.54)^2 + (-6.54)^2 + (11.46 - x)^2] / 10

= (41.7316 + 19.8916 + 2.1316 + 2.1316 + 2.1316 + 6.4516 + 6.4516 + 12.5316 + 42.8916 + (11.46 - x)^2) / 10

= (136.786) / 10

= 13.6786

Finally, we take the square root of the average of the squared deviations to find the standard deviation:

Standard deviation = sqrt(13.6786) = 3.8356

Therefore, the correct answer is option b.

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Answer: I think it’s (2x+y)•(4x2-2xy+y2)•(2x-y)•(4x2+2xy+y2)

The optimal value for x in the stochastic model is a range of values from x=6 to x=8. The stochastic model causes problems due to the uncertainty in the optimal solution and the assumptions.

With a=5, the optimal solution is x=8. However, with the addition of stochasticity and possible values for a of 3, 4, and 6, the optimal value for x becomes a range of values.

The expected value of a is 4.5, which means that there is a higher probability of a lower value for a, resulting in a lower optimal value for x. Therefore, the optimal value for x becomes x=6 when a=3 or a=4, x=7 when a=5, and x=8 when a=6.

The stochastic model causes problems because the optimal solution is no longer a fixed value but rather a range of values that are dependent on the probability distribution of a.

Additionally, this model assumes that the production time is the only constraint on production, which may not always be the case in real-world production scenarios. Therefore, the stochastic model may not accurately reflect the actual production process and could lead to suboptimal production decisions.

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[tex]L(x) = 33x + 86[/tex] represents the regression of F(x) at a = -3.

We must apply the following formula to determine the regression L(x) of the equation: [tex]F(x) = x^{3} - x^{2} + 5[/tex] at a = -3: [tex]L(x) = F'(a)(x - a) + F(a)[/tex] , where a derivative of F(x) calculated at an is denoted by F'(a).

We calculate the amount of F(-3): F(-3)

[tex]= (-3)^3 - (-3)^2 + 5[/tex]

= -27 + 9 + 5 = -13

We determine F(x)'s derivative:

[tex]F'(x) = 3x^2 - 2x[/tex]

We assess F'(-3):

[tex]F'(-3) = 3(-3)^2 - 2(-3)[/tex]

= 27 + 6 = 33

Now we can change these numbers in the L(x) formula:[tex]L(x) = -13 + 33(x + 3)[/tex]. If we condense this expression, we get: L(x) = 33x + 86

We utilise the equation [tex]L(x) = F(a) + F'(a)(x - a)[/tex], to determine the linearization of an equation at a specific point, where F(a) represents the function's value at point a and F'(a) was the function's derivative calculated at point a. We can approximate the function close to point a linearly.

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The difference in the account balances is $138,435.93.

We have,

We can solve this problem by using the formula for the future value of an annuity:

[tex]FV = PMT \times [(1 + r)^n - 1] / r[/tex]

where FV is the future value of the annuity, PMT is the yearly contribution, r is the annual interest rate, and n is the number of years.

Using the given information, we can find the future value of the annuity if the person starts at age 35:

FV1

= $5,000 x [(1 + 0.065)^30 - 1] / 0.065

= $431,874.32

Now we can find the future value of the annuity if the person starts at age 40:

FV2 = $5,000 x [(1 + 0.065)^25 - 1] / 0.065

= $293,438.39

The difference in the account balances is:

FV1 - FV2

= $431,874.32 - $293,438.39

= $138,435.93

Therefore,

The difference in the account balances is $138,435.93.

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The total amount she earned $945.75.

We have,

P= 900

bank A deposition= 550

R= 2.25%

So, the interest from Bank A

= 550/100 x 2.25

= 12.375

and, Interest from Bank B

= (900 - 550)/100 x 3

= 350/100 x 3

= 10.5

So, total she earned

= 10.5 + 12.375 = 22.875

In 2 years she will earned

= 22.875 x 2

= 45.75

Thus, the total amount she earned

= 900 + 45.75 = 945.75

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The interest rate for the savings account is 5% after 4 years, $20,000 deposited in a savings account with simple interest earned $800 in interest.

We can use the formula for simple interest to solve the problem:

Simple interest = (Principal * Rate * Time) / 100

where Principal is the initial amount deposited, Rate is the interest rate, and Time is the time period for which the interest is calculated.

We know that the Principal is $20,000 and the time period is 4 years. We are also given that the interest earned is $800. So we can plug in these values and solve for the interest rate:

$800 = (20,000 * Rate * 4) / 100

Multiplying both sides by 100 and dividing by 20,000 * 4, we get:

Rate = $800 / (20,000 * 4 / 100) = 0.05 or 5%

Therefore, the interest rate for the savings account is 5%.

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The formula for the area of a circular petri dish can be represented as A = πr², where "A" represents the area and "r" represents the radius.

To find the approximate increase in the area when the radius increases from r₁ mm to r₂ mm, we can calculate the difference between the areas by subtracting the initial area (A₁ = πr₁²) from the final area (A₂ = πr₂²). This can be expressed as ΔA = A₂ - A₁ = πr₂² - πr₁².

In the second paragraph, let's explain the formula and how to calculate the approximate increase in the area of the bacterial colony on the petri dish. The area of a circular shape is given by the formula A = πr², where "A" represents the area and "r" represents the radius. By substituting the initial radius, r₁, into the formula, we can find the initial area, A₁ = πr₁².

Similarly, by substituting the final radius, r₂, into the formula, we can find the final area, A₂ = πr₂². To calculate the approximate increase in area, we subtract the initial area from the final area: ΔA = A₂ - A₁ = πr₂² - πr₁². This formula allows us to find the difference in the areas of the bacterial colony on the petri dish when the radius increases from r₁ to r₂.

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The value of cos X is approximately given as .80000.

The correct answer choice is option C.

Hypotenuse = 50

Adjacent = 30

Opposite = 40

cos X = adjacent / hypotenuse

= 30/50

= 0.6

Cos 0.6 = 0.825335614

Approximately,

.80000

Hence, cos X is .8000

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62.8 cubic inches is the volume of a can of peanuts with a height of 5 in. and a lid that is 4 in. wide

We have to find the  volume of a can of peanuts with a height of 5 in. and

a lid that is 4 in. wide

Volume of cylinder =πr²h

h is height which is 5 in

r is radius of can which is 2 in

Plug in values of h and r

Volume = 3.14×4×5

=62.8 cubic inches

Hence, 62.8 cubic inches is the volume of a can of peanuts with a height of 5 in. and a lid that is 4 in. wide

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Answer:5+3x/4

Step-by-step explanation:

Answer:2x+1

1

​

Step-by-step explanation:

The required out of the 80 eggs laid, only 11 insects are expected to reach adulthood.

If an insect lays 80 eggs on a plant, and 70% of the eggs hatch, then the number of hatched eggs is:

80 x 0.7 = 56

Now, if 80% of the hatched eggs die before reaching adulthood, then the number of insects that reach adulthood is:

56 x 0.2 = 11.2

However, we cannot have a fractional number of insects, so we need to round this to the nearest whole number. Since we are asked for how many insects will reach adulthood, we round up if the decimal is 0.5 or greater and round down if the decimal is less than 0.5. In this case, since 0.2 is less than 0.5, we round down to get:

11 insects

Therefore, out of the 80 eggs laid, only 11 insects are expected to reach adulthood.

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The correct interpretation for the confidence interval is that with 95% confidence, the true proportion of people with kids will be in the above interval.

This means that if we were to repeat the same survey or study multiple times, about 95% of the time, the true proportion of people with kids would fall within the given interval.

It is important to note that we cannot say with certainty that the true proportion falls within the interval, as there is always a chance for sampling error or variability.

However, we can say with a high degree of confidence that the true proportion is likely to fall within the interval. Option A is incorrect because we cannot say with certainty that the true proportion is within the interval, even though it is likely. Option c is also incorrect because the confidence level refers to the long-run proportion of intervals that will contain the true value, not a probability statement about a single interval.

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Which sends 1 to 2, and then apply the permutation (1,3) to the result, which sends 2 to 3. So (1,3)(1,2) = (1,2,3), not (1,3,2).

(a) To write f as a product of transpositions, we can track the movement of each number in the permutation. Starting from 1, we see that it goes to 4, which means we can write the transposition (1,4). Next, we look at where 4 goes, which is to 6, so we can write the transposition (4,6). Continuing this process, we get:

f = (1,4)(4,6)(6,9)(9,8)(8,5)(5,2)(2,1)(7,3)

So f can be written as the product of the transpositions (1,4), (4,6), (6,9), (9,8), (8,5), (5,2), (2,1), and (7,3).

(b) To find f-1, we need to reverse the order of the transpositions in f and also reverse each transposition. For example, the transposition (1,4) becomes (4,1). Applying this process to all the transpositions in f, we get:

f-1 = (3,7)(1,2)(2,5)(5,8)(8,9)(9,6)(6,4)(4,1)

So f-1 can be written as the product of the transpositions (3,7), (1,2), (2,5), (5,8), (8,9), (9,6), (6,4), and (4,1).

(c) The rule for multiplication of permutations (fg)(x) = f(g(x)) means that we apply the permutation g to x first, and then apply the permutation f to the result. For example, if we have the permutations f = (1,2,3) and g = (1,3), then (fg)(1) = f(g(1)) = f(3) = 2. To see why this is true, note that g sends 1 to 3, and then f sends 3 to 2.

Using this rule, we can see that (1,3)(1,2) means that we apply the permutation (1,2) first, which sends 1 to 2, and then apply the permutation (1,3) to the result, which sends 2 to 3. So (1,3)(1,2) = (1,2,3), not (1,3,2).

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Chaneece did not find the correct solution

From the question, we have the following parameters that can be used in our computation:

x and y are the integers

So, we have

x + y ≤ 40

x - y ≥ 20

Add the equations

So, we have

2x = 60

Divide

x = 30

Next, we have

30 + y ≤ 40

So, we have

y ≤ 10

This means that

x = 30 or between 20 and 30

y = 10 or between 0 and 10

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D. 80% of the surveyed customers like the taste of the pizza topping. This is an example of descriptive statistics because it describes a specific group of 50 customers who were surveyed and their response to the new topping.

Descriptive statistics are used to summarize and describe data, often by using measures such as percentages, means, and standard deviations. In this case, the percentage of customers who liked the new topping is a descriptive statistic that summarizes the data collected from the survey.

This answer represents descriptive statistics because it summarizes and describes the information collected from the specific sample of 50 customers who participated in the taste test. It does not make assumptions or predictions about the entire population or customer base, but instead focuses solely on the data collected from the sample group.

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This statement is generally true.

When hydrogen is added to the structure of an oil through a process called hydrogenation, the oil becomes more saturated with hydrogen atoms, which reduces the amount of double bonds in the oil's molecules. This can cause the melting point of the oil to decrease and the oil to become more liquid and easier to pour. Additionally, hydrogenated oils tend to have a longer shelf life and are more stable at high temperatures, making them useful in many food processing applications.

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The given parabola has its vertex at the origin and the directrix as a horizontal line passing through the point (0,-7), and the equation is y^2 = 28x, which opens to the right. So, the correct answer is A) The student's answer is correct.

To determine if the student's answer is correct, we need to check if the equation of the parabola and the direction of its opening match the given conditions.

The given parabola has its vertex at the origin and the directrix as a horizontal line passing through the point (0,-7). Therefore, the axis of symmetry is the y-axis, and the focus is located at (0,7).

The standard equation of a parabola with the vertex at the origin and the directrix as a horizontal line passing through the point (0,-p) is y² = 4px, where p is the distance from the vertex to the directrix. In this case, p = 7, so the equation of the parabola is y² = 28x.

The coefficient of x in the equation is positive, indicating that the parabola opens to the right. Therefore, the student correctly determined the direction of the parabola as well.

Hence, the answer is A. The student's answer is correct.

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The total surface area of the triangular prism is 204 square units.

To find the total surface area of a triangular prism, we need to find the areas of all its faces and add them up.

First, we need to find the area of each triangular face. We can use the formula:

Area of a triangle = 1/2 x base x height

For the triangle with base 4 and height 3, we have:

Area of triangle = 1/2 x 4 x 3 = 6

For the triangle with base 6 and height 8, we have:

Area of triangle = 1/2 x 6 x 8 = 24

Now, we need to find the area of each rectangular face. We can use the formula:

Area of a rectangle = length x width

For the rectangular face with length 6 and width 4, we have:

Area of rectangle = 6 x 4 = 24

For the rectangular face with length 8 and width 4, we have:

Area of rectangle = 8 x 4 = 32

Finally, we add up all the areas to get the total surface area:

Total surface area = 2 x (area of triangle) + 3 x (area of rectangle)

Total surface area = 2 x (6 + 24) + 3 x (24 + 32)

Total surface area = 60 + 144

Total surface area = 204

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Find The Total Surface Area Of This Triangular Prism: