A traffic engineer recorded the speeds of cars driving past herhouse, where the speed limit read 20 mph. The mean of a sample of 100 readings was 23.87 mph, with a standard deviation of 3.61 mph.

Using a Normalmodel, what values should border the middle95% of all carspeeds?

The cutoff points for the middle95% of all car speeds are

nothing

mph and

nothing

mph.

(Use ascending order. Round to two decimal places asneeded.)

b) The accompanying table lists some summary statistics. From your answer in parta, how well does the model do in predicting thosepercentiles? Are yousurprised? Explain.

The cutoff points for the actual middle95% of car speeds are

nothing

mph and

nothing

mph, which are

close to

very different from

the predicted values. Since the distribution is

strongly left skewed,

approximately normal,

strongly right skewed,

we

should not

should

be surprised.