Question 32620
Recall, the average (mean) of a set of numbers is the sum of the numbers divided by how numbers there are.
So, if we add up (sum) the temperatures for the 3 days and divide by 3 we get the average temperature for those days.
{{{(120.25 + 94.45 + x)/3 = 102.26}}} Solve for x.  Multiply both sides by 3.
{{{214.7 + x = 306.78}}} Subtract 214.7 from both sides.
{{{x = 92.08}}}