Answer:
Step-by-step explanation:
Hello!
The variable of interest in this case is:
X: length of time before a major repair is required on a new car. (months)
This variable has a normal distribution with mean μ= 36 months and a standard deviation σ= 9 months.
If he wants to set a guarantee period in which only 5% of the sold cars fell, the objective is to find the value of X that has below 5% of the cars that need major repairs before the end of the guarantee period.
Check the attachment, the curve represents the distribution of the population of the time it takes before a new car needs major repairs, I've marked approximately where this value of X should be.
Symbolically:
P(X≤a)=0.05
To reach the proper value of "a" you have to work using the standard normal distribution because is a tabulated distribution and you can extrapolate it to any normal distribution.

So the first step is to look in the table of the Z distribution for the value that accumulates 0.05 of probability since it is such a low probability, you have to look for the value in the left side of the table (negative values of Z). You look for 0.05 in the body of the table and then the margins for the corresponding value (see second attachment)

Then the value that accumulates 0.05 of probability is -1.64, now you have to reverse the standardization to reach the asked value of X
Z= (a- μ)/σ
(Z*σ)= a - μ
a=(Z*σ)+ μ
a=(-1.64*9)+36
a= 21.24 months.
The guarantee period should be 21.24 months so that only 5% of the sold cars will need major repairs before it wears of.
I hope it helps!
Well I can’t see where x would be therefore I can’t tell you how to get to x
Maybe use a Calculator and multiple the two number?
Answer: -3x is a term
Step-by-step explanation: Any number that has a variable after it is a term. Another way to look at it is any grouping of a number and a variable. If the number stands alone, it's not a term, and if it is being added to something, it is an equation.
<h3>
So the equation which will tell the amount of water is</h3><h3>
W= 24 + 32 T</h3>
Step-by-step explanation:
Given,
A water tank already contain 24 gallons of water before the pump was switched to fill it. The pump started 10:00 am and by 10:30 am the tank contained 40 gallons of water . By 1:00 pm the tank contained 120 gallons of water.
The pump filled the tank (40 -24) = 16 gallons in 30 mins.
The pump filled (16 × 2 ) gallons =32 gallons in 1 hour.
So the equation which will tell the amount of water is
W= 24 + 32 T