Question

1. jamie has taken three math tests. her scores were 88, 94, and 95. to have an average of 94 after taking one more test, what must be the sum of all four tests? what score does jamie need to make on the fourth test so that her math average is 94?

oa) sum = 372; needed score = 94
ob) sum = 376; needed score = 99
oc) sum = 388; needed score = 103
od) sum = 376; needed score = 98

Explanation:

Step1: Calculate the sum of four tests

The formula for the average $\bar{x}=\frac{\text{Sum of data}}{\text{Number of data}}$. Given $\bar{x} = 94$ and the number of data $n = 4$.
Using the formula $\text{Sum}=n\times\bar{x}$, we have $\text{Sum}=4\times94=376$.

Step2: Calculate the score of the fourth test

Let the score of the fourth test be $x$. The sum of the first three tests is $88 + 94+95=277$.
Since the sum of four tests is $376$, then $x=376-(88 + 94+95)$.
$x=376 - 277=99$.

Answer:

B. Sum = 376; needed score = 99