Write and solve an equation to find the value of the variable. 104, 137, 154, 131, x; mean = 130a. 124b. 125c. 127d. 122

The answer is 124 (B).

Given a dataset , the mean is computed by summing all the item in the dataset, and then dividing the result by the number of item, i.e.

In your case, the dataset has the following 5 items: 104, 137, 154, 131 and x.

So, the mean is

And we want it to be 130, so we pose

Multiply both sides of the equation by 5 to get rid the denominator:

Subtract 526 from both sides to solve for x:

the answer is b.)

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