Question 40713
Sam's average score, including the score of x on his last test must be at least 70.(70 or more)

The average (mean) is found by adding the four scores and dividing the sum by 4, and this must be 70 or more.

{{{(75+63+68+x)/4 >= 70}}}
{{{(206+x)/4 >= 70}}} Multiply both sides by 4.
{{{206+x >= 280}}} Subtract 206 from both sides.
{{{x >= 74}}} This is the inequality representing the score that Sam must get on the last test.