Question

The owner of a convenience store keeps track of how many customer buy lunch food during the "noon rush" each day for four days and calculates that the mean number of customers for those four days is 52. How many customers must come in on the fifth day to make the five-day mean 54?
a) 54
b) 60
c) 62

Answer 1

Answer:

c) 62.

Step-by-step explanation:

Let x represent number of customers came in on the fifth day.

We have been given that the mean number of customers for those four days is 52. So total number of customers on 4 days would be 4 times 52 that is 208 customers.

We know that mean of a data set is equal to sum of all data points divided by number of data points.

Total number of customers on 5 days would be $208+x$ and total number of days is 5.

Since we need a mean of 54, so we can set mean of 5 days equal to 54 as:

$\frac{208+x}{5}=54$

Multiply both sides by 5:

$\frac{208+x}{5}*5=54*5$

$208+x=270$

$208-208+x=270-208$

$x=62$

Therefore, 62 customers must come in on the fifth day to make the five-day mean 54 and option 'c' is the correct choice.