A scientist notes the bacteria count in a petrie dish is 40. Three hours later, she notes the count has increased to 75. Using an exponential model, how many hours will it take for the bacteria count to grow from 75 to 120? Express the answer to the nearest tenth of an hour. Hint: You are NOT looking for the total time to reach 120. You are looking for the elapsed time from 75 to 120.

Percentage Change = (new rate - old rate) / (old rate)

New Rate = 11.5

Old Rate = 10

(11.5 - 10) / 10

1.5 / 10 = 15 / 100 = 0.15 = 15%

The percentage change in her hourly rate is 15%.

Hope this helps!

Answer:

the answer to this question is 1.08

The experiment of rolling the dice and selecting a card is an illustration of probabilities

The probability of selecting a red card and rolling a number less than 3 is 1/6

From the figure, we have:

Total outcomes = 12

Red card with a number less than 3 = 2

So, the probability of selecting a red card and rolling a number less than 3 is:

p = 2/12

Simplify

p = 1/6

Hence, the probability of selecting a red card and rolling a number less than 3 is 1/6

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The probability is 0.1429.

The probability that the first person chosen is a boy is 5/7. The probability that the second is a boy is 4/6; the third, 3/5; and the fourth, 2/4. Both the numerator and denominator decrease every time, because you lose a boy to choose from and you lose a student to choose from as well. This gives us:

5/7(4/6)(3/5)(2/4) = 120/840 = 0.1429.

The probability that everyone in the group is a girl is 2/7.

Probability sampling is defined as a sampling technique in which the researcher chooses samples from a larger population using a method based on the theory of probability.

Total number of students in a class = 7

Number of boys students = 2

Number of girls students = 5

The probability that everyone in the group is a girl is;

[tex]\rm Probability =\dfrac{Total \ number \ of \ girls}{Total \ number \ of \ boys}\\\\Probability=\dfrac{2}{7}[/tex]

Hence, the probability that everyone in the group is a girl is 2/7.

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#SPJ4

Answer:

25.12

Step-by-step explanation:

C = π2r
C = 3.14*2*4
C = 25.12
Hope this helps :)

Answer:

we're u asking for this

What is ur statistical question

Answer:

  D.  x = -5

Step-by-step explanation:

The square root function is only defined for non-negative arguments. For the function ...

  [tex]g(x)=\sqrt{x+4}[/tex]

this means we must have ...

  x +4 ≥ 0

  x ≥ -4 . . . . . . subtract 4 from both sides

All of the numbers on your answer choice list are more than -4 except -5.

  x = -5 is not in the domain of g(x)

now, let's make the assumption that the arcXZ has a central angle of 135° and a radius of 17.

[tex]\textit{arc's length}\\\\ s=\cfrac{\theta \pi r}{180}~~ \begin{cases} r=radius\\ \theta =\stackrel{degrees}{angle}\\[-0.5em] \hrulefill\\ r=17\\ \theta =135 \end{cases}\implies s=\cfrac{(135)\pi (17)}{180}\implies s=\cfrac{51\pi }{4}\implies s\approx 40.06[/tex]

Answer:

h = 8 units, b = 20 units

Step-by-step explanation:

h = 2 units
2 x 4 = 8

b = 5 units
5 x 4 = 20 units

Therefore, h = 8 units and b = 20 units

Hope this helps :)

Step-by-step explanation:

8x – 2y = -30 } ×2

16x - 4y = -60

–9x + 4y = 18

___________

7x=-42

x=-6

8(-6)-2y=-30

-2y=-18

y=9

Answer:

(-6,-9)

Step-by-step explanation:

The quickest way is to solve with elimination. Multiply the top equation by 2.

2(8x – 2y = -30)

16x-4y=-60

16x-4y=-60

–9x + 4y = 18

7x=-42

x=-6

8x – 2y = -30

8(-6) – 2y = -30

-48-2y=-30

-2y=18

y=-9

Answer:56Step-by-step explanation:7k²=21952

k²=21952/7

k²=3136

k=√3136

k=56

PLS MARK ME AS BRAINLIEST

The conic water vessel of height 40 cm and radius 8 cm filled at 20 cm^3/s gives;

The volume of the vessel, v = π•r^2•h/3

[tex] \frac{h}{r} = \frac{40}{8} = 5[/tex]

h = 5•r

Therefore;

v = π•r^2•(h)/3 = π•(h/5)^2•h/3

v = π•h^3/75

By chain rule of differentiation, we have;

[tex] \frac{dv}{dh} = \frac{dv}{dt} \times \frac{dt}{dh} [/tex]

Which gives;

[tex]π• \frac{ {h}^{2} }{25} = 20 × \frac{dt}{dh} [/tex]

[tex] \frac{dh}{dt} = \frac{20}{\pi \frac{ {h}^{2} }{25} } [/tex]

When the height is 12 cm from the vertex, we have;

[tex] \frac{dh}{dt} = \frac{20}{\pi \frac{ {12}^{2} }{25} } = 1.1 [/tex]

When the vessel is one-quarter filled, we have;

v = π•h^3/75

π•(40)^3/(75×4) = π•h^3/75

10•(40)^2 = 16,000 = h^3

h = (16,000)^(1/3) = 25 (approx)

Which gives;

[tex] \frac{dh}{dt} = \frac{20}{\pi \frac{ {25}^{2} }{25} } = 0.21 [/tex]

When the vessel is one-quarter filled the rate at which the water level is rising is approximately 0.21 cm/s.

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Answer:

Let F = customer's fare (in dollars)

Let d = distance traveled (in miles)

Given:

Creating an equation from given information:

F = 2d + 5

This is a linear equation, with slope of 2 and y-intercept of (0, 5)

**see attached graph**

Answer:

See below ↓

Step-by-step explanation:

Given :

Solving :

Answer:

681 m^3

Step-by-step explanation:

Winder only found part of the volume. He also needs to find the volume of the hemisphere.

I would first find the volume of the cylinder like Winder, then proceed to calculate the volume of the hemisphere, which is V = 4/3π(4^3)=27.16 m^3. The total volume inside the storage tank is 681 m^3 when rounded to the nearest cubic meter.

Answer:

Base=8.4 inches

Step-by-step explanation:

Area of triangular bandana is 38sq inches

Height of triangle is 9 inches

Area of ∆ =½×b×h

38=½×b×9

38×2=b×9

76/9=b

b=8.4 inches

Answer:

d

Step-by-step explanation:

so if you look at the bottom left corner you can see 1 box is the same as saying for every second someone walks its one metre.

thats not how i got the answer though.

if you look at the starting point at 8 because she was 8 meters away you need to see when she comes across her first second which after 2 meters (Goes down two squares before reaching the first second)

now technically soe of the other answers are correct too but heres how i thought about it.

A. its correct but i dont think that's what its asking you for tbh

B. This we don't know for sure. eg she could take 890 seconds walking back to her starting point we just don't know for sure.

C. This is also true but once again it's easily given to you so i dont think that's what you're being asked.

D. This is the only option where you had to do any for of working out because s=d/t so s=8/4=2m/s

Answer: A

Step-by-step explanation:

Answer:

the answer is 529

Step-by-step explanation:

see the explanation photo

On average, people visit Thrillville 2 more times per year than Funland.

To determine how many more times per year, on average, do people visit Thrillville than Funland, the following calculation must be performed:

Therefore, on average, people visit Thrillville 2 more times per year than Funland.

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Answer:

  13 units

Step-by-step explanation:

A right triangle can be drawn using the grid lines for legs and the line segment between the two points as the hypotenuse. You can count grid squares or subtract coordinates to find the vertical leg is 12 units and the horizontal leg is 5 units. The Pythagorean theorem tells you the length of the hypotenuse (distance between the points) is ...

  d² = 12² +5² = 144 +25 = 169

  d = √169 = 13

The distance between the two points is 13 units.

_____

Additional comment

This set of dimensions, {5, 12, 13}, is one of several "Pythagorean triples" that often show up in math problems. Other common triples are {3, 4, 5}, {7, 24, 25}, {8, 15, 17}, {9, 40, 41}, and multiples of these.

Answer: C

Step-by-step explanation:

Given:

Sample size (n) = 50

x = 12

[tex]\widehat{\mathbf{p}}=\frac{\mathbf{x}}{n}=\frac{12}{50}=0.24[/tex]

Confidence level = 90%

α = 1 − 0.90 = 0.10

α/2 = 0.05

[tex]\text { Critical value }\left(z_{c}\right)=z_{\frac{\alpha}{2}}=z_{0.05}=1.6449[/tex]

(from standard normal table)

90% Confidence interval is,

[tex]\begin{aligned}&\text { Confidence interval }=\widehat{\mathbf{p}} \pm z_{c} \times \sqrt{\frac{\hat{\mathbf{p}}(1-\hat{\mathbf{p}})}{n}} \\&\text { C. I }=0.24 \pm 1.6449 \times \sqrt{\frac{0.24(1-0.24)}{50}} \\&\text { C. I }=0.24 \pm 1.65 \times \sqrt{\frac{0.24(1-0.24)}{50}}\left\end{aligned}[/tex]

Therefore, 90% confidence interval for the true proportion of sophomores who favour the adoption of uniforms is C

Answer:

498. 498/6 = 83.

Step-by-step explanation:

Answer:

3/4 · 1/4 = 3/16

Step-by-step explanation:

We can see from the picture that

yellow is

4 boxes out of the entire group of 16 boxes, hence 4/16

OR simplified

1 horizontal strip out or 4 total same horizontal strips, hence 1/4

blue is

12 boxes out of the entire group of 16 boxes, hence 12/16

OR simplified

3 vertical strips out or 4 total vertical strips, hence 3/4

The multiplication problem is

1/4 · 3/4 = 3/16 or 3/4 · 1/4 = 3/16

The result is 3 green boxes out of all 16 boxes.

(3/16 can not be simplified)

Answer:

1 = 3/2

2 = -1/14

Step-by-step explanation:

The equation for the slope of a line is [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex] (difference in Y divided by the difference in X) or simply just Rise/Run.

For the first one, we have to pinpoint two points on the graph. There's one point placed on the x-axis 2 units away from the origin (2,0) and one four units to the right and 3 units up from the origin (4,3). Since it's on a graph, the easiest way to calculate it is by counting the units up and then right from (2,0) to (4,3). You can count that (4,3) is 3 units up and 2 units right from (2,0). Since slope is Rise/Run, the slope is 3/2.

For the second one, you can use the equation [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]. The Y of the second point is 2, and the Y of the first point is 1. The X of the second point is -17, and the X of the first point is -3.

You can plug all 4 numbers in to get (2-1)/(-17- -3)

2-1 = 1 and -17 - -3 = -14. So your slope is 1/-14 or -1/14.

Answer:

each pet bird got 1/8 of the bag of birdseed

Step-by-step explanation:

the easiest way to do this is to divide the bag into eighths. if you divide the bag into eighths, 4/8 of the bag, being half, goes into the bird feeder. the other 4/8 of the bag is divided among Mr. Wilson's four pet birds, leaving each bird to get 1/4 of the bag when split evenly.

hope this helps

Using the z-distribution, as we are working with a proportion, it is found that the 83% confidence interval is (0.5789, 0.7611).

A confidence interval of proportions is given by:

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which:

In this problem, we have an 83% confidence level, hence[tex]\alpha = 0.93[/tex], z is the value of Z that has a p-value of [tex]\frac{1+0.83}{2} = 0.915[/tex], so the critical value is z = 1.37.

The other parameters are [tex]n = 50, \pi = 0.67[/tex].

Then, the bounds of the interval are given as follows:

[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.67 - 1.37\sqrt{\frac{0.67(0.33)}{50}} = 0.5789[/tex]

[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.67 + 1.37\sqrt{\frac{0.67(0.33)}{50}} = 0.7611[/tex]

The 83% confidence interval is (0.5789, 0.7611).

More can be learned about the z-distribution at https://brainly.com/question/25890103

Answer:

CI = (57.89%, 76.14%)

Step-by-step explanation:

First, solve for the 83% critical z-value (za/2). Second, solve for the margin of error. Third, solve for the confidence interval by subtracting and adding the margin of error with the sample probability of success.

Answer:

a dupli-CATE

Step-by-step explanation:

HAHAHAHA OMG THIS IS ACTUALLY FUNNY

Answer:

20 - 2n

n = a number