The Professor's Response

Hi professor, I have encountered a couple of problems in section 5.2 hw when they ask to find the probability between numbers. Number 20, asks for the probability for a randomly selected dieter on the plan he is on to loose between 5 and 10 pounds. So when i draw it, i shade in what is between 5-10, but then there is 2 empty spaces everything below 5 and after 10, so I am not sure how i am supposed to calculate after i get the z scores?

Then 25) its finding the probability between 145 and 146, so I find the z score for 145, which is 0.4207, and 146 is 0.2673, now what calculation do i have to do because i am stuck in the same position as #20, since is it a shaded part in the same side, i do not know what to do, maybe i am shading wrong?

Then for 29) I get that z score of 0.2486 and 0.4032, and i was adding them, but it is the wrong answer. I shaded between 110 and 120 on the right side?

31) I found the z scores as well 0.4192 and 0.3413, but i do not know what to do with the numbers, since i shaded in between 155 and 165.

Thank you in advance,

Natassia

See the professor's answer below.

Hi Natassia,

In each of the questions you are asking about, the problems deal with what I call the "**Same-Side-Subtract**" case. If you have two z-scores on the **same side** of the curve, and you are shading between them, you will **subtract** the probability values from the z-table to solve the problem.

The attached video deals with this case. Let me know if you have any further questions on this topic.

Professor McGuckian