Answer:
Step-by-step explanation:
To find the coordinates of the point is 1/4 of the way from A (-6, -3) to B (6, 1), we are going to be using the midpoint formula, which states that:
The midpoint is at . Where:
Then, the midpoint is at:
=
Now, to find the coordinates of the point that is 1/4 of the way, we are going to calculate the midpoint between the point 'A' and the midpoint previously caculated, as follows:
⇒ =
Therefore, the point is 1/4 of the way from A to B is:
Answer:
He must survey 123 adults.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the z-score that has a p-value of .
The margin of error is:
Assume that a recent survey suggests that about 87% of adults have heard of the brand.
This means that
90% confidence level
So , z is the value of Z that has a p-value of
, so
.
How many adults must he survey in order to be 90% confident that his estimate is within five percentage points of the true population percentage?
This is n for which M = 0.05. So
Rounding up:
He must survey 123 adults.