# Question: A school board administrator believes that the average number of days

A school-board administrator believes that the average number of days absent per year among students is less than 10 days. From past experience, he knows that the population standard deviation is 3 days. In testing to determine whether his belief is true, he could use one of the following plans:

i. n = 100, α = .01

ii. n = 75, α = .05

iii. n = 50, α = .10

Which plan has the lowest probability of a Type II error, given that the true population average is 9 days?

i. n = 100, α = .01

ii. n = 75, α = .05

iii. n = 50, α = .10

Which plan has the lowest probability of a Type II error, given that the true population average is 9 days?

## Answer to relevant Questions

a. A random sample of 25 was drawn from a population. The sample mean and standard deviation are x̄ = 510 and s = 125. Estimate µ with 95% confidence.b. Repeat part (a) with n = 50.c. Repeat part (a) with n = 100.d. ...a. The sample mean and standard deviation from a sample of 81 observations are x̄ = 63 and s = 8. Estimate e with 95% confidence.b. Repeat part (a) with n = 64.c. Repeat part (a) with n = 36.d. Describe what happens to the ...A random sample of 8 observations was drawn from a normal population. The sample mean and sample standard deviation are x̄ = 40 and s = 10.a. Estimate the population mean with 95% confidence.b. Repeat part (a) assuming that ...A courier service advertises that its average delivery time is less than 6 hours for local deliveries. A random sample of times for 12 deliveries to an address across town was recorded. These data are shown here. Is this ...To help Estimate the size of the disposable razor market, a random sample of men was asked to count the number of shaves they used each razor for. Assume that each razor is used once per day. Estimate with 95% confidence the ...Post your question