Question

ann is participating in a 6 - day cross - country biking challenge. she biked for 59, 50, 68, 54, and 62 miles on the first five days. how many miles does she need to bike on the last day so that her average (mean) is 58 miles per day?

Explanation:

Step1: Calculate the total miles needed for 6 days

The formula for the mean (average) is $\text{Mean}=\frac{\text{Sum of values}}{\text{Number of values}}$.
If the mean is $58$ miles per day for $6$ days, then the total miles needed is $58\times6 = 348$ miles.

Step2: Calculate the sum of miles for the first 5 days

Sum of first - five - day miles: $59 + 50+68 + 54+62=(59 + 62)+(50 + 54)+68=121+104 + 68=293$ miles.

Step3: Calculate the miles needed on the last day

Let $x$ be the miles needed on the last day.
We know that $293+x=348$.
Solving for $x$, we get $x = 348-293=55$ miles.

Answer:

$55$