According to exponent rules, whne we multiply exponential expressions we__

The tread life of a particular brand of tire is a random variable best described by a normal distribution with a mean of 60,000

valina [46]

Answer: 61,750 miles

Step-by-step explanation:

Given : The p-value of the tires to outlast the warranty = 0.96

The probability that corresponds to 0.96 from a Normal distribution table is 1.75.

Mean : $\mu=60,000\text{ miles}$

Standard deviation : $\sigma=1000\text{ miles}$

The formula for z-score is given by : -

$z=\dfrac{x-\mu}{\sigma}\\\\\Rightarrow\ 1.75=\dfrac{x-60000}{1000}\\\\\Rightarrow\ x-60000=1750\\\\\Rightarrow\ x=61750$

Hence, the tread life of tire should be 61,750 miles if they want 96% of the tires to outlast the warranty.

3 0

2 years ago

a red hot ar balloon is 100 feet off the ground and is rising at a rate of 8 feet per second. a green hot air balloon is 160 fee

zhenek [66]

Answer:

it would be a fraction of a sec

Step-by-step explanation:

see if you just simply took out a calculator you would see its not possible unless you knew what the balloon is descending at during the fraction of the seconds

7 0

3 years ago

Find x so that the points (x,x+1), (x+2,x+3) and (x+3,2x+4) form a right-angled triangle.

azamat

Let a, b, and c be vectors each starting at the origin and terminating at the points (x, x + 1), (x + 2, x + 3), and (x + 3, 2x + 4), respectively.

Then the vectors a - b, a - c, and b - c are vectors that point in directions parallel to each of the legs formed by the triangle with these points as its vertices.

If this triangle is to contain a right angle, then exactly one of these pairs of vectors must be orthogonal. In other words, one of the following must be true:

(a - b) • (a - c) = 0

or

(a - b) • (b - c) = 0

or

(a - c) • (b - c) = 0

We have

a - b = (x, x + 1) - (x + 2, x + 3) = (-2, -2)

a - c = (x, x + 1) - (x + 3, 2x + 4) = (-3, -x - 3)

b - c = (x + 2, x + 3) - (x + 3, 2x + 4) = (-1, -x - 1)

Case 1: If (a - b) • (a - c) = 0, then

(-2, -2) • (-3, -x - 3) = (-2)×(-3) + (-2)×(-x - 3) = 2x + 12 = 0 ==> x = -6

which would make a - c = (-3, 3) and b - c = (-1, 5), and their dot product is not zero. Then the triangles vertices are at the points (-6, -5), (-4, -3), and (-3, -8).

Case 2: If (a - b) • (b - c) = 0, then

(-2, -2) • (-1, -x - 1) = (-2)×(-1) + (-2)×(-x - 1) = 2x + 4 = 0 ==> x = -2

which would make a - c = (-3, -1) and b = (-1, 1), and their dot product is also not zero. The vertices are the points (-2, -1), (0, 1), and (1, 0).

Case 3: If (a - c) • (b - c) = 0, then

(-3, -x - 3) • (-1, -x - 1) = (-3)×(-1) + (-x - 3)×(-x - 1) = x ² + 4x + 6 = 0

but the solutions to x here are non-real, so we throw out this case.

So there are two possible values of x that make a right triangle, x = -6 and x = -2.

3 0

3 years ago

Which is the completely factored form of 3xsquared -12x-15?

tekilochka [14]

Answer:

3(x - 5)(x + 1).

Step-by-step explanation:

3x^2 - 12x - 15

Dividing through by 3:

= 3(x^2 - 4x - 5)

We need 2 numbers whose sum is -4 and whose product = -5. That is -5 and +1 , so the factors are:

3(x - 5)(x + 1).

7 0

2 years ago

Is on in which every member of the population has an equal chance of being selected for the sample?

Fittoniya [83]

This type of sampling would be Random Sampling.

5 0

3 years ago

According to exponent rules, whne we multiply exponential expressions we___the exponents