# Question: A simple random sample of 60 items resulted in a

A simple random sample of 60 items resulted in a sample mean of 80. The population standard deviation is σ = 15.

a. Compute the 95% confidence interval for the population mean.

b. Assume that the same sample mean was obtained from a sample of 120 items. Provide a 95% confidence interval for the population mean.

c. What is the effect of a larger sample size on the interval estimate?

a. Compute the 95% confidence interval for the population mean.

b. Assume that the same sample mean was obtained from a sample of 120 items. Provide a 95% confidence interval for the population mean.

c. What is the effect of a larger sample size on the interval estimate?

## Answer to relevant Questions

A 95% confidence interval for a population mean was reported to be 152 to 160. If σ = 15, what sample size was used in this study?For a t distribution with 16 degrees of freedom, find the area, or probability, in each region.a. To the right of 2.120b. To the left of 1.337c. To the left of – 1.746d. To the right of 2.583e. Between – 2.120 and ...There has been a trend toward less driving in the last few years, especially by young people. From 2001 to 2009 the annual vehicle miles traveled by people from 16 to 34 years of age decreased from 10,300 to 7900 miles per ...In developing patient appointment schedules, a medical center wants to estimate the mean time that a staff member spends with each patient. How large a sample should be taken if the desired margin of error is two minutes at ...A sample containing years to maturity and yield for 40 corporate bonds is contained in the data file named CorporateBonds (Barron’s, April 2, 2012).a. What is the sample mean years to maturity for corporate bonds and what ...Post your question