# Hypothesis Test

• July 23rd 2013, 04:32 PM
jpoll
Hypothesis Test

Suppose that you want to test the claim that the mean weight of male harbor seals is 40 pounds. You collect a sample of 100 seals and find that the mean weight in the sample is 40.8 pounds.The standard deviation is 4.

Using significance level of 0.01 test the null hypothesis using 5-step procedure.
• July 23rd 2013, 05:24 PM
HallsofIvy
Re: Hypothesis Test
Okay, if you are asked to use the "5 step procedure" you should know what that procedure is! What are the "5 steps"?

I don't know what you mean by the "5 step procedure" so I can't help you there. What I would do is find corresponding 'standard z value' for the standard normal distribution (with mean 0 and standard deviation 1). That is given by $z= \frac{40.8- 40}{4}= .2$. Then look up the probability of that z-value in a table of the standard normal distribution. (A good one on the internet is at Standard Normal Distribution Table) Is the probability of that greater than 1.00- 0.01= 0.99?
• July 23rd 2013, 07:26 PM
jpoll
Re: Hypothesis Test
Sorry about that! The 5 step procedure is pictured here http://i.imgur.com/dSR2hG1.jpg. I think I see where to go with this one but now I'm stuck on a similar problem below.

Suppose that you want to test the claim that the mean weight of male harbor seals is 40 pounds or less. You collect a sample of 100 seals and find that the mean weight in the sample is 40.8 pounds. The standard deviation is 4 pounds.