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:
0.00000381469
Step-by-step explanation:
there u go
S*.05= ?*.05
I'm not really sure
Answer:
It'll take 38.3 years to obtain the desired return of $25,000.
Step-by-step explanation:
In order to solve a continuosly coumponded interest question we need to apply the correct formula that is given bellow:
M = C*e^(r*t)
Where M is the final value, C is the initial value, r is the interest rate and t is the time at which the money was applied. Since he wants an return of $25,000 his final value must be the sum of the initial value with the desired return. So we have:
(25000 + 8000) = 8000*e^(0.037*t)
33000 = 8000*e^(0.037*t)
e^(0.037*t) = 33000/8000
e^(0.037*t) = 4.125
ln[e^(0.037*t)] = ln(4.125)
t = ln(4.125)/(0.037)
t = 1.4171/0.037 = 38.2991
t = 38.3 years