Question

question 1 of 7
cameron took 4 tests, and his scores were as follows:
100, 60, 80, and 30. cameron took another test that
was scored x. the mean score of the 5 tests he took is

1. what is the value of x?

54
67
68
90

Explanation:

Step1: Recall the formula for the mean

The mean (average) of a set of numbers is calculated by the sum of the numbers divided by the count of the numbers. The formula is $\text{Mean} = \frac{\sum_{i = 1}^{n} x_{i}}{n}$, where $n$ is the number of values and $x_{i}$ are the individual values.

Step2: Calculate the sum of the known scores

Cameron's first 4 test scores are 100, 60, 80, and 30. The sum of these scores is $100 + 60 + 80 + 30$. Let's calculate that: $100+60 = 160$, $160 + 80 = 240$, $240+30 = 270$.

Step3: Set up the equation for the mean of 5 tests

Now, he has taken 5 tests (the 4 original ones plus the new one with score $x$). The mean of the 5 tests is 72. Using the mean formula, we have $\frac{270 + x}{5}=72$.

Step4: Solve for $x$

Multiply both sides of the equation by 5 to get rid of the denominator: $270 + x = 72\times5$. Calculate $72\times5 = 360$. Then, subtract 270 from both sides: $x = 360 - 270$.

Step5: Calculate the value of $x$

$360 - 270 = 90$.

Answer:

90