Kathy recorded the following measurements of length: 2.5 cm.
2.9 cm, 3.0 cm, 2.5 cm, and 3.1 cm. What is the mean for this
set of values, in cm?

2.8

Step-by-step explanation:

To find the mean add all the values and divide by the amount of values and when you add everything up it is 14 and dividr by 5 to get 2.8

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

144.50

step-by-step explanation:

21.5 x 13.4=288.10 divide by 2