Question

The number of hours per week that the television is turned on is determined for each family in a sample. The mean of the data is 31 hours and the median is 27.2 hours. Twenty-four of the families in the sample turned on the television for 16 hours or less for the week. The 7th percentile of the data is 16 hours. Step 2 of 5: Approximately how many families are in the sample? Round your answer to the nearest integer.

Answer 1

Answer :

Given 24 of all families in the sample turned on the television for 16 hours or less for week ,

16 hours is the 7 th percentile

let n be the total number of families

the 7 th percentile has the property that that 7 ie  

7 % * n = 24

Rewrite the percentage as a decimal by dividing the numeral by 100 and removing % sign

ie ( 7 /100 ) * n = 24

multiply each side by 100 we get ,

7 * n = 2400

divide each side by 7

n = 2400 / 7

n = 342 . 8571 ie approximately = 343

Conclusion : There are about 343 families in the sample .