Step-by-step explanation:

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:

Answer:
the faster cyclist was going 18 mph
the slower cyclist was going 9 mph
Step-by-step explanation:
72 ÷ 4 = 18
18 ÷ 2 = 9
4
one of the functions equals 0 while the other equals 4
0+4=4
Answer:
FV= $160.68
Step-by-step explanation:
Giving the following information:
Initial investment= $150
Interest rate= 3.5% compounded annually
Number of periods= 2
T<u>o calculate the future value, we need to use the following formula:</u>
FV= PV*(1+i)^n
PV= present value
i= interest rate
n= number of periods
FV= 150*(1.035^2)
FV= $160.68