Answer:
9 months
Step-by-step explanation:
3*12-27
36-27
9
Answer:
95% Confidence interval for the variance:

95% Confidence interval for the standard deviation:

Step-by-step explanation:
We have to calculate a 95% confidence interval for the standard deviation σ and the variance σ².
The sample, of size n=8, has a standard deviation of s=2.89 miles.
Then, the variance of the sample is

The confidence interval for the variance is:

The critical values for the Chi-square distribution for a 95% confidence (α=0.05) interval are:

Then, the confidence interval can be calculated as:

If we calculate the square root for each bound we will have the confidence interval for the standard deviation:

Part 1)
we have
------> equation A
------> equation B
Multiply by
the equation A
------> equation C
Multiply by
the equation B

-------> equation D
Adds equation C and equation D

therefore
<u>the answer Part 1) is the option A </u>

Part 2)
we have
------> equation A

Simplify Divide by
both sides

------> equation B
the lines A and B are parallel lines, because the slope m is equal
so
The system has no solution
therefore
<u>the answer Part 2) is the option D</u>
There is no x value as there is no solution to the system.
Part 3)
we have
------> equation A

------> equation B
substitute equation B in equation A
![4x+2[x-3]=6](https://tex.z-dn.net/?f=4x%2B2%5Bx-3%5D%3D6)



therefore
<u>the answer part 3) is the option D</u>

Part 4)
Let
x---------> The number of one-step equations
y---------> The number of two-step equations
we know that

-------> equation A
------> equation B
substitute equation A in equation B
![3[1,120-y]-2y=1,300](https://tex.z-dn.net/?f=3%5B1%2C120-y%5D-2y%3D1%2C300)




therefore
<u>the answer part 4) is the option D</u>

Answer:
he pays $18.19 hope this helps have a nice day please give me brainliest
Step-by-step explanation:
- 47 → d
using the ' product rule '
(uv) = uv' + vu' = (3 × - 4) + (7 × - 5 ) = - 12 - 35 = - 47