If 30% of his collection is 12 cars, then we can use the fraction
30/12=100/x
x=40
I can't think of what the form is called, but the slope is in that equation.
y=mx+b
m is the slope and in that equation, m=-4/3
The correct answer is the last set of numbers
Answer:

Step-by-step explanation:
He got the slope wrong and the y-intercepz wrong
Answer:

And then the maximum occurs when
, and that is only satisfied if and only if:

Step-by-step explanation:
For this case we have a random sample
where
where
is fixed. And we want to show that the maximum likehood estimator for
.
The first step is obtain the probability distribution function for the random variable X. For this case each
have the following density function:

The likehood function is given by:

Assuming independence between the random sample, and replacing the density function we have this:

Taking the natural log on btoh sides we got:

Now if we take the derivate respect
we will see this:

And then the maximum occurs when
, and that is only satisfied if and only if:
