Researchers planning a study of the reading ability of third-grade children want to obtain a 95% confidence interval for the population mean score on a reading test, with margin of error no greater than 3 points. They carry out a small pilot study to estimate the variability of test scores. The sample standard deviation is s = 12 points in the pilot study, so in preliminary calculations the researchers take the population standard deviation to be sigma equals 12.

a) The study budget will allow as many as 100 students. Calculate the margin of error of the 95% confidence interval for the popu

Question

Researchers planning a study of the reading ability of third-grade children want to obtain a 95% confidence interval for the population mean score on a reading test, with margin of error no greater than 3 points. They carry out a small pilot study to estimate the variability of test scores. The sample standard deviation is s = 12 points in the pilot study, so in preliminary calculations the researchers take the population standard deviation to be sigma equals 12.

a) The study budget will allow as many as 100 students. Calculate the margin of error of the 95% confidence interval for the popu