Michael is participating in a 5-day cross-country biking challenge. He biked for \( 49,51,64 \), and 53 miles on the first four days. How many miles does he need to bike on the last day so that his average (mean) is 54 miles per day? miles

To find out how many miles Michael needs to bike on the last day to achieve an average of 54 miles over the 5 days, we first calculate the total miles he must bike for 5 days. The formula for average is given by: \[ \text{Average} = \frac{\text{Total miles}}{\text{Number of days}} \] Therefore, the total miles needed over 5 days = 54 miles/day * 5 days = 270 miles. Now, we sum the miles he has already biked: 49 + 51 + 64 + 53 = 217 miles. To find out how many more miles he needs to bike on the last day: 270 - 217 = 53 miles. So, Michael needs to bike **53 miles** on the last day to achieve his goal.