The mean of four numbers is 30. If three of the numbers are 12, 50, and 48, what is the fourth number? A. 120
B. 10
C. 12
D. 30

Here’s the

Step-by-step explanation:

The sum of the four numbers divided by 4 is equal to the mean.

the sum/4 = mean

(12 + 50 + 48 + n)/4 = 30

(110 + n)/4 = 30

(110 + n) = 30 × 4

(110 + n) = 120

n = 120 - 110

n = 10

2 over 5

step-by-step explanation:

the 2: 3 ratio is the length of the ac segment to the cb segment total length. this implies that the ratio between segment ac length and segment ab length is 2: 5. point c is 2/5 from a to b, so the required fraction is 2/5.

4 and 5)16.97 or 12√2

6)15.59 or 9√3

7)y = 15.59 or 9√3     x =27

8)17.80