A journal article reports that a sample of size 5 was employed as a basis for computing a 95% interval for true average nature frequency (Hz) of delaminated beams of the certain type. The resulting interval was (229.764, 233.504).
a. What was the sample mean?
b. You decide that a condence level of 99% is more appropriate. Compute the 99% interval for the true average nature frequency (Hz).