posted by joe .
Each of the following is a confidence interval for u = true average(population mean) resonance frequency (Hz) for all tennis rackets of a certain type: (114.4, 115.6) (114.1, 115.9)
A) What is the value of the sample mean resonance frequency?
B) Both intervals were calculated from the same sample data. The confidence level for one of the intervals is 90% and for the other is 99%. Which of the intervals has the 90% confidence level, why?