Question

45 POINTS!!! The mean of 4 data values is calculated. One of the data values is 3 above the mean. Another value is 4 above the mean. A third value is 1 above the mean. What is true about the fourth value?
A) It is 8 below the mean.

B) It is 6 below the mean

C) It is equal to the mean

D) It is 2 above the mean

Answer 1

Answer:

A) It is 8 below the mean.

Step-by-step explanation:

Let x be the mean

Value 1  is x+3

Value 2 = x+4

Value 3 = x+1

Value 4 = y

The means is found by adding all the values together and dividing by the number of values

Mean = (Value 1 + value 2 + value 3 + value 4 )/4

x = (x+3 + x+4+x+1 + y)/4

Multiply each side by 4

4x = (x+3 + x+4+x+1 + y)

Combine like terms

4x = 3x +8 + y

Subtract 3x from each side

4x-3x =3x-3x y+8

x = y+8

Subtract 8 from each side

x-8 = y+8-8

x-8 =y

The 4th number is 8 below the mean since x is the mean