The Professor's Response

Hi Professor,

Question on Homework Problem number 14 under section 5.3. When I solve for the z-score I get -3.04 but then the I get stuck because I am not getting the right answer.

Among women aged 15 to 44, average age at first sexual intercourse was 17.3 years. Their male
counterparts lost their virginity at 17.0 years on average both groups had a standard deviation of
2.17 years. What is the probability that a randomly chosen group of 36 females lost their virginity
at an age under 16.2 years old?

Thank you.

  See the professor's answer below.

Professor McGukian

Hi Natalie,

If you found the correct z-score of -3.04, I am not sure why the rest of the problem would give you any difficulty. However, I created a video to show how the entire problem is done. Watch it to look for your error.

Professor McGuckian


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