Question

1. if the varience of a national accounting examination is 850 , how large a smaple is needed to estiamte the true mean score within 5 points with 99% confidence? Round the intermeditate calculations to 2 decimal places and the final answer to the next whole number.

The reasearcher needs at least a sample of ____ scores.

2.It is desired to estimate the mean GPA of each undergradute class at a large universty. How large a sample is necesssary to estimate the GPA within 0.27 at the confidence level? The population standard devation is 1.3.

The universty needs at least a smaple of _____ students .

Answer 1

1.

= 850

Confidence interval = 99%

The critical value = = 2.58

Margin of error = E = 5

n = 226

2.

Confidence interval = 99%

The critical value = = 2.58

Margin of error = E = 0.27

n = 154