Question

kaitlin is participating in a 5-day cross country biking challenge. She biked for 55,67,56,and 49 miles on the first four days. How many miles does she need to bike on the last day so that her average (mean) is 55 miles per day?

Answer 1

The mean of a set of values is the sum of the data divided by the number of entries. So in this case:

$\frac{55+67+56+49+x}{5} =55$

Solve for x:

55 + 67 + 56 + 49 + x = 5(55)

227 + x = 275

x = 48

The answer is 48 miles.