The following data points represent the number of points scored last basketball game by each player on the Dragons basketball team. 5,8,11,7,?

If the mean of the data set is 8 points, find the missing number of points.

9

Step-by-step explanation:

There are 5 data points.  To find the mean, we add the data and divide by 5

(5+8+11+7+?) /5 = 8

Multiply each side by 5

(5+8+11+7+?) /5 *5 = 8*5

(5+8+11+7+?)  = 40

Combine like terms

? + 31 = 40

Subtract 31 from each side

? +31-31 = 40-31

? = 9

The missing number is 9

answer is x<

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15