Question 3 Part four

[Lydia Ebel]

I think I understand how to do the other problems for #3, but part 4 I don't know how to do. How would I find the answer for between 80 and 90?

[Taeho Kim]

Hi Lydia,

This is essentially the same question to part 2 with different cutoffs.
If you was able to handle part 2, then this can be solved in a similar way.
The general approach to find out the probability between two cutoffs can be found the examples in the previous lecture.