The Environmental Protection Agency records data on the fuel economy of many different makes of cars. Data on the mileage of 20 randomly selected cars are listed below. The values are ordered for convenience. 12 13 15 16 16 17 18 18 19 19
20 20 22 23 24 26 26 27 27 29
What is the interquartile range for the mileage data?
A) 8.5 miles per gallon
B) 16.5 miles per gallon
C) 17 miles per gallon
D) 25 miles per gallon

A) 8.5 miles per gallon

Step-by-step explanation:

Given

Required

The IQR

This is calculated as:

Calculate

Remove bracket

This means that:

is the mean of 5th and 6th item

From the given data:

So, we have:

Calculate

Remove bracket

This means that:

is the mean of 15th and 16th item

From the data:

So:

Recall that:

answer

explanation

the area of a circle is calculated using the formula

or

we can use any of the above formulae to calculate the required. preferably, let us use the latter since the diameter is

we substitute the diameter into the formula to get:

this is the exact value for the area of the circle.

the correct answer is a