The two intervals 1149 1157 and 1146 1160 are confidence int

The two intervals (114.9, 115.7) and (114.6, 116.0) are confidence intervals (computed 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 of the sample mean resonance frequency?

Solution

because, confidence intervals are symmetric about sample means!
sample mean resonance frequency = (1/2)(114.4+115.6) or (1/2)(114.1+115.9)    = 115.....