The life expectancy of a particular brand of tire is normally distributed with a mean of 40,000 and a standard deviation of 5,000 miles. What is the probability that a randomly selected tire will have a life of exactly 47,500 miles

the probability that a randomly selected tire will have a life of exactly 47,500 miles is 0.067

Step-by-step explanation:

Since the life expectancy of a particular brand of tire is normally distributed, we would apply the formula for normal distribution which is expressed as

z = (x - µ)/σ

Where

x = life expectancy of the brand of tire in miles.

µ = mean

σ = standard deviation

From the information given,

µ = 40000 miles

σ = 5000 miles

The probability that a randomly selected tire will have a life of exactly 47,500 miles

P(x = 47500)

For x = 47500,

z = (40000 - 47500)/5000 = - 1.5

Looking at the normal distribution table, the probability corresponding to the z score is 0.067

the correct answer is you spend $55.78 more in a brand store that buy ing in a normal store.

step-by-step explanation:

brand = spend   $ 135.85 total

store = spend $80.07 total

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