You gather data from two local churches about the average offering (a monetary donation to the church)that is collected at a weekly service. You want to see whether the average offering given at one churchis the same as the average offering at another church. The number of people who attend Church 1 is201, and the average amount offered is $12.50. The number of people who attend Church 2 is 350, andthe average amount offered is $11.87. The sample standard deviations for Church 1 and Church 2 are$3.15 and $4.57, respectively.
(a) What is the hypothesis you want to test?
(b) Calculate the test statistic and test your hypothesis at the 95 and 99 percent confidence levels.
(c) Pretend that the sample means and standard deviations remain the same, but that the numberof people sampled at Church 2 was 201 instead of 350. Does your test-statistic change? Does thecritical value change?