Dr. ilvento uses a smart phone app to track the distance he walks. while taking the same walk each time, he noticed the distance stated in the app varied a lot. so he began to record the distance in an experiment. he also recorded the distance in a car and found it to be consistently 2.4 miles. the data and some summary information are given below. assume this comes from a normal distribution. this is a small sample mean problem.

answer: slight chance that it will happen

step-by-step explanation:

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