The two intervals 1144 1156 and 1141 1159 are confidence int

The two intervals (114.4, 115.6) and (114.1, 115.9) are confidence intervals 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? in hertz

(b) The confidence level for one of these intervals is 90% and for the other it is 99%. Which one is has a confidence level of 99%?

A. (114.4, 115.6)

B. (114.1, 115.9)   

Solution

a)

Sample mean = (upper+lower)/2 = (114.4 + 115.6)/2 = 115 [ANSWER]

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b)

The wider one should be the larger confidence level, 99%, so

OPTION B: (114.1, 115.9) [ANSWER]