Question

A supermarket selected a sample of 160 of its customers and measured how long they took to be served at the checkout counter. If too many customers wait too long, the supermarket intends to hire more checkout personnel. Specifically, the supermarket would like at least 86% of its customers to be checked out in 8.6 minutes or less. From the data, the 90th and 60th percentiles were computed to be 8.8 minutes and 7.3 minutes, respectively. The range of the data was 12 minutes and the fastest anyone was checked out was 1.8 minutes. Step 1 of 5: What was the longest time (in minutes) anyone waited in line

Answer 1

The longest time (in minutes) anyone waited in line was 13.8

Explanation:

The range of a set is the subtraction of the highest value by the lowest.

In this problem:

Range of 12 minutes.

The fastest anyone was checked out was 1.8 minutes.

What was the longest time (in minutes) anyone waited in line

I am going to call the longest time x

The range being 12 means that x - 1.8 = 12

So

x - 1.8 = 12

x = 13.8

The longest time (in minutes) anyone waited in line was 13.8