keith is participating in a 4 - day cross - country biking challenge. he biked for 78, 60, and 68 miles on…
keith is participating in a 4 - day cross - country biking challenge. he biked for 78, 60, and 68 miles on the first three days. how many miles does he need to bike on the last day so that his average (mean) is 67 miles per day?
Answer
Explanation:
Step1: Calculate total miles needed
The average is 67 miles per day for 4 days. So the total miles needed is the average times the number of days. $67\times4 = 268$
Step2: Calculate total miles biked in first 3 days
Add the miles biked in the first three - days: $78 + 60+68=206$
Step3: Calculate miles needed on last day
Subtract the total miles biked in the first three days from the total miles needed. $268 - 206=62$
Answer:
62