Answer:
C.
Step-by-step explanation:
15+14+13=42
Hope this helps :)
I cant answer if there is no info
Answer: C. 12.5
Step-by-step explanation:
Given : A manufacturer of new light bulbs claims the average lifetime of its long-life bulb is more than 4000 hours.
Population mean : 
Sample size : n= 100
Sample mean : 
Standard deviation: 
The value of test-statistic is given by :-

Hence, the value of the test statistic for this problem is 12.5.
Answer:
the answer should be 18
Step-by-step explanation:
this isnt exactly hard when you get the first part with ST beeing 36 then you can just halve that and the answer is 18
Answer:
We do not have the equation for the part B, so we can not aswer it correctly.
But i will give a general answer.
We could have infinite answers always when we have more variables than linear independent equations:
This is, if we have one variable, x, we can have infinite solutions if we have no equations (or equations with no restrictions for our variable)
So if we have an equation like:
x*4 = √16*x
you can see that both sides of the equation are exactly the same, so this equation actually does not have any value, and x could take infinite different values and the equation will remain true.
If we have two variables, x and y, we will have infinite solutions if we have only one equation:
y = a*x + b
We have infinite pairs (x, y)