Question

Brenda’s scores on the first three of four 100-point science tests were 95, 92, and 89. What score does she need on her fourth science test to ensure an average score of at least 93?. . A) X ≥ 96. B) X ≤ 90. C) X ≥ 88. D) X ≤ 92

Answer 1

Average of 93

4 scores
(95+92+89+x)/4>93
times 4 both sides
276+x>372
minus 276 both sides
x>96


A

Answer 2

The average is equal to the mean of the data set. It is the total of the data or numbers given divided by the ordinal unit of the data set. In this case, we are given with scores of 95, 92, and 89. To have an average of at least 93, the fourth score should be : 
95 + 92 + 89 + x ≥ 93 * 4 where 4 is the number of data points. 
x ≥ 96. Test score should be equal or greater than 96.