Answer:
a) The expected number of smokers in a random sample of 140 students from this university is 16.8 smokers.
b) No, it is unlikely that smoking habits and waking up early to go to the gym on Saturday are independent.
Step-by-step explanation:
To calculate the expected numbers of smokers in a sample with size n=140 and proportion p=12%, we use the expected value of the binomial distribution:

The expected number of smokers in a random sample of 140 students from this university is 16.8 smokers.
If we take a sample at the opening of the gym, the sample is not expected to be representative of the population of the students. Most of the students that go to the gym usually have healthy habits, so the proportions of smokers is expected to be lower than the average of the university population.

In other words, how many ways are there to choose

objects from a total of

objects? Just one; take all of them at the same time.
Answer:
yes
Step-by-step explanation:
As an example
(x₁, y₁ ) = (1,2) and (x₂, y₂ ) = (5,3), then
d =
=
=
= 
Now let (x₁, y₁ ) = (5,3) and (x₂, y₂ ) = (1,2), then
d =
=
=
= 
Answer:
(0,-2)
Step-by-step explanation:
First we find the equation of the line passes through
and
.
The slope of the line is

So by the point slope formula the equation of the line is

When
we have
.
Therefore the line joining the two points cuts the y-axis at (0,-2).