The Professor's Response

Can you please show how you solved question #30 in section 8.4 which says the following:

Use the given information to find the p-value:

Claim: µ < 15 Test Stat: Z = 1.58

Thank you.

  See the professor's answer below.

Professor McGukian

Hi Joe,
This is a good one to ask about.  Notice, it is a left-tailed hypothesis test since Ha has a < symbol.   This means we have to find the area to the left of the test statistic in order to find the p-value.  The area to the left of 1.58 is greater than 50% since 1.58 is on the right half of the curve.  When we look up 1.58 we get 0.4429 for the area from 1.58 to 0.  We then have to add 0.5000 to account for the left half of the curve.  The final answer is 0.9429. 

Hope that helps,

Professor McGuckian

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