# Question: a The sample mean and standard deviation from a random

a. The sample mean and standard deviation from a random sample of 10 observations from a normal population were computed as x̄ = 23 and s = 9. Calculate the value of the test statistic of the test required to determine whether there is enough evidence to infer at the 5% significance level that the population mean is greater than 20.

b. Repeat part (a) with n = 30.

c. Repeat part (a) with n = 50.

d. Describe the effect on the t-statistic of increasing the sample size.

b. Repeat part (a) with n = 30.

c. Repeat part (a) with n = 50.

d. Describe the effect on the t-statistic of increasing the sample size.

## Answer to relevant Questions

a. A statistics practitioner is in the process of testing to determine whether there is enough evidence to infer that the population mean is different from 180. She calculated the mean and standard deviation of a sample of ...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. Test the following hypotheses with α = .05 given that x̄ = 405, s = 100, and n = 1,000.H0: µ = 400H1: µ > 400b. Repeat part (a) assuming that you know that the population standard deviation is σ = 100.c. Explain why ...An increasing number of North Americans regularly take vitamins or herbal remedies daily. To gauge this phenomenon, a random sample of Americans was asked to report the number of vitamin and herbal supplements they take ...Estimate with 95% confidence the mean numbers of earners (EARNRS) in the household in 2012.Post your question