Question

Jenny James has score of 78 89 90 and 96 on her first four test what score should she make out of 100 points in order to have at least an average of 90

Answer 1

Jenny James would need to have a score of 97 out of 100 points in order to have an average of 90.

Explanation:

Given that:

Scores of four tests

78, 89, 90 and 96

Let,

x be the score on fifth test.

Average is the sum of quantities divided by total number of quantities.

Average = 90

Average =
`(Sum\ of\ scores)/(No.\ of scores)`

Putting the values in the formula;

`90=(78+89+90+96+x)/(5)\\90=(353+x)/(5)\\90*5=353+x\\450=353+x\\450-353=x\\x=97`

Hence,

Jenny James would need to have a score of 97 out of 100 points in order to have an average of 90.