Find the standard deviation for the indicated sets of numbers. A calculator may be used.

The miles traveled in Exercise 15

Data from Exercises 15

Use the following data. In testing a new electric engine, an automobile company randomly selected 20 cars of a certain model and recorded the range (in mi) that the car could travel before the batteries needed recharging. The results are shown below.

Using the classes 141−44, 144 −147, . . . , 153−156, form a frequency distribution table. Use the convention that the left endpoint is included in each class, but not the right endpoint.

143, 148, 146, 144, 149, 144, 150, 148, 148, 144 153, 146, 147, 146, 147, 149, 145, 151, 149, 148