Question

The distances in miles driven by a sample of nine different cars using 13 gallons of gasoline were 174, 201, 271, 208, 196, 340, 214, 236, and 385. Find the mean and the standard deviation for the distances traveled. How many cars fall within one standard deviation of the mean?

Answer 1

When You order the numbers you get

174 196 201 208 214 236 271 340 385

To get the mean, you add up all the numbers

Sum:2225

Then you divide it by how many test subjects there are (9 cars)

2225÷9=247.222222222 Which is your mean

Q1 is between 196 and 201

Q3 is between 271 and 340

If you get the mean of both, Q1 would be 198.5 and Q3 is 305.5

The amount of cars between them is 6