Answer:
Step-by-step explanation:
Total distance = 3 + 2.5 = 5.5mi/h
Total time = 0.75h + 2hr = 2. 75 hr
Average speed = 5.5 / 2.75 = 2
The following are the heat-producing capacities of coal from two mines (in millions of calories per ton): Mine A: 8,500, 8,330, 8,480, 7,960, 8,030 Mine B: 7,710, 7,890, 7,920, 8,270, 7,860. Assuming that the data constitute independent random samples from normal populations with equal variances, construct a 99% confidence interval for the difference between the true average heat-producing capacities of coal from the two mines.
Answer: The confidence interval will be -91.87 < μ₁-μ₂ <751.87
Step-by-step explanation: Confidence Interval is the interval of certainty in which the true population mean is in.
In a confidence interval for the difference between two averages with a sample size less than 30, the calculations are:
[tex]x_{1}-x_{2}[/tex] ± [tex]t.S_{p}\sqrt{\frac{1}{n_{1}} +\frac{1}{n_{2}} }[/tex]
in which
x₁ and x₂ are the sample mean of each data set
t is the probability found in the t-table whose df = n₁ + n₂ - 2
[tex]S_{p}[/tex] is the pooled estimate of the common standard deviation, assuming variances are similar, and can be calculated as:
[tex]S_{p}=\sqrt{\frac{(n_{1}-1)(s_{1})^{2}+(n_{2}-1)(s_{2})^{2}}{n_{1}+n_{2}-2} }[/tex]
n₁ and n₂ are sample sizes
The data to construct the interval are:
Mine A:
x₁ = 8260
s₁ = 251.9
n₁ = 5
Mine B:
x₂ = 7930
s₂ = 206.52
n₂ = 5
Then:
[tex]S_{p}=\sqrt{\frac{(5-1)(251.9)^{2}+(5-1)(206.52)^{2}}{8}[/tex]
[tex]S_{p}=\sqrt{\frac{253814.44+170602.04}{8}[/tex]
[tex]S_{p}=[/tex] 230.33
Using a table, for a 99% confidence and df = 8, t-score = 2.896.
Doing calculations:
(8260-7930) ± (2.896)(230.33)([tex]\sqrt{\frac{1}{5} +\frac{1}{5} }[/tex])
330 ± (2.896)(230.33)([tex]\sqrt{0.4}[/tex])
330 ± 421.87
Interval will be
[tex]-91.87<\mu_{1}-\mu_{2}<751.87[/tex]
A 99% confidence interval for the difference between the true average heat-producing capacities of coal from the mines is between -91.87 and 751.87
need help with last two questions plsssss help
Answer:
The answer for desert is 34.986 clicks, or 35 clicks rounded up. You get this by multiplying 4.2 and 8.33.
The answer for fuschia is 6 clicks, and you get this by multiplying 0.75 and 8.
Henry is making a corn grits recipe that calls for 14 cup of corn grits for every 12 cup of water.
How much water will he need if he uses 112 cups of corn grits?
Answer:
2 cups of water
Step-by-step explanation:
Drag the correct steps into order to solve for 5x+5=-20 for x.
Answer:
x= -5
Step-by-step explanation:
Simplifying
5x + 5 = -20
Reorder the terms:
5 + 5x = -20
Solving
5 + 5x = -20
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-5' to each side of the equation.
5 + -5 + 5x = -20 + -5
Combine like terms: 5 + -5 = 0
0 + 5x = -20 + -5
5x = -20 + -5
Combine like terms: -20 + -5 = -25
5x = -25
Divide each side by '5'.
x = -5
Simplifying
x = -5
4(a+3) - 7 = 6a -21 aaaaaaaaaaaaaaaaaa
Answer:
a=13
Step-by-step explanation:
4a+12-7=6a-21
combine like terms
4a+5=6a-21
sub 4a from each side
5=2a-21
add 21 to each side
26=2a
divide each side by 2
a=13
Answer:
:)
Step-by-step explanation:
a=13
What is the y-intercept of the quadratic function
f(x)= (- 8)(x +3)?
Answer:
-24
Step-by-step explanation:
The standard from of equation of a line is expressed as g(x) = mx+c where;
m is the slope
c is the y-intercept of the line.
Given the expression g(x)= (- 8)(x +3), rewriting in standard form first we have;
g(x)= (- 8)(x +3)
gx)= -8x - 24
On Comparing with g(x) mx+ c, we will see that;
c = -24
Hence the y-intercept of the quadratic function is -24
What is the answer for
(1, 1) and (1,9)
Answer:
9/0
Step-by-step explanation:
what is the solution of sqaure root -4x = 100
Answer:
I’m pretty sure it’s -2500
Step-by-step explanation:
Answer:
I think it would be x = -2500
Step-by-step explanation:
You square both sides to get rid of the square root and get -4x = 10000 then divide 10000 by -4 to get -2500
Susan gets a haircut that cost $20 she leaves a 15% tip. she also has to pay 8.4% sales tax. how much will it cost.
Answer:
$24.68
Step-by-step explanation:
15% of 20=3
8.4% of 20=1.68
20+3+1.7=24.68
I did this by multiplying .15 by 20 to get 3, and multiplying .084 by 20 to get 1.68. Again, add it all together to get $24.68.
Hope this helps :)
PLEASE HEL0 :( 20 points!
Answer:
a c b and f
Step-by-step explanation:
c
2.5
What is the midpoint of the line segment between points (2,6) and (3,8)?
O (2,5.5)
O (2.5, 2)
O (5, 4.5)
O (4, 5.5)
O (2.5, 7)
The answer is (2.5,7)
Player 1 and player 2 are running laps around a field. Player 1 runs 1 lap every 4 minutes, while player 2 runs 1 lap every 15 minutes. If player 1 and player 2 begin their run at the same time and location on the field, in how many minutes will they meet to begin their next lap together?
Answer:
15 min
Step-by-step explanation:
if it takes Player 1 one min he will meet player two at there second lap after 15 min
If player 1 and player 2 begin their run at the same time and location on the field, In 60 minutes will they meet to begin their next lap together.
What is LCM?The LCM of any two is the value that is evenly divisible by the two given numbers.
Given,
Player 1 and player 2 are running laps around a field
Player 1 runs 1 lap every 4 minutes,
player 2 runs 1 lap every 15 minutes
We need to find in how many minutes will they meet to begin their next lap together
We need to find the LCM of 4 and 15 to find the answer
4: 4, 8,12,16, 20,24,28,32,36,40,44,48,52,56,60
15: 15,30,45,60
The least common multiple of 4 and 15 is 60.
The two players meet at the same point after 60 minutes.
Hence If player 1 and player 2 begin their run at the same time and location on the field, In 60 minutes will they meet to begin their next lap together.
To learn more on LCM click:
https://brainly.com/question/28932085
#SPJ2
What is the population density of 13 lillies living in an area of 6 meters (length) and 4 meters (width)?
Answer:
0.54 lillies per square meter.
Step-by-step explanation:
First we calculate the area:
Area = length * width
Area = 6 m * 4 m = 24 m²
The we divide the population of lillies (13) by the area, to calculate the population density:
13 lillies / 24 m² = 0.54 lillies/m²
So the population density is 0.54 lillies per square meter.
Directions: Find the value of x.
102
(9x +12)
Answer:
10
Step-by-step explanation:
you subtract 12 from 102 and get 90. then you divide 90 by 9 and it equals 10. to figure these problems out I always do the order of operations in reverse starting with the answer.
The last time it placed an order for ingredients, Sweet Treats Bakery ordered 9,160 kilograms of sugar. This time, the bakery is ordering 75% more sugar. How much sugar is that?
Answer:
Sry but i hope u get the right answer and have a great christmas.
Step-by-step explanation:
A store owner offered a 25% discount off the regular price of a pair of shoes. The amount of the discount is $4.
What is the regular price of the shoes?
A $8
B $12
C $20
D $16
Answer:
D
Step-by-step explanation:
25% of 16 is 1/4x16=4, which leaves D as as your answer
Answer:
d
Step-by-step explanation:
instead of taking away 4 add it until you have 100%
Need help please it’s due today show work
Answer:
30+ deg -10 =20+deg
so answer is see mark brainliest plz
Which expression represents the following calculation?
"Add 2 and 10, then multiply by 3, then add 9."
Answer:
I think it's...
[(2 + 10) × 3] + 9
$5.99 for 18 lb this is the question
Travis bought 8 new books for $7.99 each. How much did he spend on books?
Answer:
$63.92
Step-by-step explanation:
Evaluate the expression 4² -3.4+ 7
Answer:
19.6
Step-by-step explanation:
there
The book store is having a sale. Every book is $5 off, regardless of the original price.
The sale price for every book is $5 less than the original price.
Let x = original price
Let y = sale price
Which equation represents this situation?
A. y = × + 5
B. y = × - 5
C. y = 5x
D. y = × ÷ 5
Answer:
y=x-5
Step-by-step explanation:
sale price (y) is equal to the original (x) minus five dollars
Answer:
y = x - 5
Step-by-step explanation:
I took the test on A P E X
HELP ME PLEASE I AINT GOT NO MORE WNERGY helpppppppp
Answer:
copy and paste youll get it
Step-by-step explanation:
Answer:
1350
Step-by-step explanation:
humm
which numbers are rational A)-4.34
B)0.43222
C)7.234156
Answer:
C
Step-by-step explanation:
The other 2 aren't rational numbers
I am not completely confident in my answer, so lmk if it's right
HELP ASAPPP PLZZZZ!
Answer:
the second statement isn't true
Answer:
its the 2nd one
Step-by-step explanation:
have a good day
10 points for correct answer and giving brainliest
Answer:
A
Step-by-step explanation:
We know it cant be -6 as that would be a range and since the circle on the end is hallow it wont be less or equal to rather just less than and the since the next one is 2 and its solid circle it has to be less than or equal too
Answer:
A. -9 < x ≤ -2
General Formulas and Concepts:
Algebra I
Domain is the set of x-values that can be inputted into function f(x)Step-by-step explanation:
According to the graph, the line's x-values span from -9 to 2. Since -9 is an open dot, it is exclusive in the domain. Since 2 is a closed dot, it is inclusive in the domain:
(-9, 2] or -9 < x ≤ -2
ASAP PLS HELPPPPPPPPPPPP ME ITS DUE TODAY!!!!!
WILL MARK BRAINLIEST IF GOOD ANSWER
Rewrite 7 − 8 using the additive inverse and display the new expression on a number line. (5 points)
Select one:
a.
7 + (−8)
An image of a horizontal number line is shown with labels from negative 2 to positive 8. An arrow begins at 0 and ends at 7. Another arrow begins at 7 and ends at negative 1.
b.
7 + 8
An image of a horizontal number line is shown with labels from 0 to 15. An arrow begins at 0 and ends at 7. Another arrow begins at 7 and ends at 15.
c.
7 − (−8)
An image of a horizontal number line is shown with labels from 0 to 15. An arrow begins at 0 and ends at 7. Another arrow begins at 7 and ends at 15.
d.
8 − 7
An image of a horizontal number line is shown with labels from negative 2 to positive 8. An arrow begins at 0 and ends at 8. Another arrow begins at 8 and ends at 1.
Answer:
i believe it is b
Step-by-step explanation:
Answer: B
Step-by-step explanation:
It is B because It would be the inverse of the equation, which is the opposite of the equation and It is 7+8.
The gas tank and Bob's car has 2.5 gallons of gas left in it Bob filled his gas tank and paid $45 the price for a gallon of gas was $3.05 approximately how many gallons of gas does Bob's tank hold
Answer:
45 divided by $3.05= 14.75
14.75 + 2.5 gallons = 17.25 gallons
Approximate volume gas tank will hold is 17 gallons.
Step-by-step explanation:
Complete the table by converting the fractions (in the first column) into decimals (in the second column) and vice versa. Fractions Decimals -4/5 1 2/100 0.13 3/4
Answer:
Step-by-step explanation:
-4/5=-8/10=-0.80
12/100=0.12
0.13=13/100
3/4=75/100=0.75
Please solve this question
3x-9<12
Answer:
Step-by-step explanation:
3x-9<12
You carry the 9 to the other side and do the inverse(opposite of take away
3x<12+9
3x<21
3x/3x
To cancel out the the x you must devide them together and then devide 21÷3
21/3=7
X<7
Answer: x<7 or (-infinity,7)
Step-by-step explanation:
3x-9<12
3x<21
x<7