The total score of five tests is 500. Then she needs to score on the fifth test so that the mean will be 90% is 94.
Mean is simply defined as the average of the given set of numbers. The mean is considered as one of the measures of central tendencies in statistics. The mean is said to be an arithmetic mean. It is the ratio of the sum of the observation to the total number of observations.
Marissa has taken four 100- point tests in math this semester. Her mean score is 89%.
She needs marks in test 5 so that the mean will be 90%. Then we have
The sum of the score of four tests will be
[tex]\begin{aligned}\rm \dfrac{Obtained \ marks}{Total \ test } &= \rm Mean\\\\\dfrac{\rm Obtained \ marks}{4} &= 89\\\\\rm Obtained \ marks &= 356 \end{aligned}[/tex]
Let x be the marks in the 5th test. Then we have
[tex]\begin{aligned}\rm \dfrac{Obtained \ marks}{Total \ test } &= \rm Mean\\\\\dfrac{\rm x + 356}{5} &= 90\\\\\rm x + 356 &= 450\\\\ \rm x &= 94 \end{aligned}[/tex]
The score on the fifth test is 94.
More about the mean link is given below.
https://brainly.com/question/521501
