The mean of four numbers is 30 if three of those numbers are 12,50,and 48 what is the fourth number?
120
10
12
30
Mean and , outliers, quick Chek
To find the fourth number, we can use the formula for the mean:
Mean = (sum of all the numbers) / (total number of numbers)
We can substitute the given values:
30 = (12 + 50 + 48 + x) / 4, where x is the fourth number we're looking for.
Multiplying both sides by 4 gives:
120 = 12 + 50 + 48 + x
Simplifying, we get:
x = 120 - 12 - 50 - 48
x = 10
Therefore, the fourth number is 10.
Quick check:
We can verify that the mean of all four numbers is indeed 30 by adding them up and dividing by 4.
(12 + 50 + 48 + 10) / 4 = 30
So, the answer is option B, 10.