The two intervals (114.6, 115.8) and (114.3, 116.1) are confidence intervals (calculated using the same sample data) for = true average resonance frequency (in hertz) for all tennis rackets of a certain type. (a) What is the value (in hertz) of the sample mean resonance frequency? (Hint: Where is the confidence interval centered?) hertz (b) The confidence level for one of these intervals is 90% and for the other it is 99%. Which one has a confidence level of 99%? (114.6, 115.8) (114.3, 116.1) It is impossible to tell which is which. How can you tell? The 99% confidence interval should be narrower than the 90% confidence interval. The 99% confidence interval should be wider than the 90% confidence interval. The center of the 99% confidence interval should be less than the center of the 90% confidence interval. The center of the 99% confidence interval should be greater than the center of the 90% confidence interval. It is impossible to tell which is which.