Question 598411
Data was collected from 74 mature great white sharks and they had a mean of 13.8 feet and a standard deviation of 2.7 feet. Furthermore, 23 0f those sharks were over 16 feet long. 
a. can you say at the .01 significance length that average length of a mature great white shark is less than 15 feet?
-------------------------------
Ho: u >= 15
Ha: u < 15 claim
------
x-bar = 13.8
z(13.8) = (13.8-15)/[2.7/sqrt(74)] = -3.8233
----
p-value = P(z < -3.8233) = normalcdf(-100,-3.8233) = 0.00006586
---
Since the p-value is less than 1%, reject Ho.
The test results support the claim.
========================================
Cheers,
Stan H.