What equation do you use?

6.82 Drivers' Test in Small Towns Toronto drivers have been going to small towns in Ontario (Canada) to take the drivers' road test, rather than taking the test in Toronto, because the pass rate in the small towns is 90%, which is much higher than the pass rate in Toronto. Suppose that every day, 100 people independently take the test in one of these small towns. a. What is the number of people who are expected to pass? b. What is the standard deviation for the number expected to pass? c. After a great many days, according to the Empirical Rule, on about 95% of these days the number of people passing the test will be as low as and as high as d. If you found that on one day, 89 out of 100 passed the test, would you consider this to be a very high number