Question

jamie has taken three math tests. her scores were 85, 90, and 89. to get an average of 90 what must be the sum of all her tests ? what score does she need on the fourth test so that her mean score is 90 ?

Answer 1

96 marks

Explanation:

We know that the mean of a given amount of values is the sum of the values divided by the number of values

Let the marks in the fourth test = x marks

Mean of the values = 90

(85 + 90 + 89 + x) / 4 = 90

264 + x = 360

x = 96

Therefore, Jamie needs 96 marks in her 4th test to get a mean score of 90