Question

Penny earned a 74% on her first test. If each test has 100 points, what must she earn on her next test to achieve an average of at least 80%?

Answer 1

Explanation:

the mean value is average is the sum of all data divided by the number of data points.

with the second test she will have 2 data points.

the first was 74 points (74% of 100 points = 74 points).

x = 2nd test result

(74 + x)/2 = 80

74 + x = 160

x = 86

she must earn 86% on her second test to achieve an average score of 80%.