Answer:
Step-by-step explanation:
4/20 + 11/20 = 15/20
15/20 = 3/4 or 0.75
Answer:
Step-by-step explanation:
A linear equation can be written in the form
y = mx+b.
y = x² is not linear.
Answer:
The 95% confidence interval for the fraction of all shoppers during the year whose visit was because of a coupon they'd received in the mail is (0.2016, 0.2694).
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
.
A store randomly samples 603 shoppers over the course of a year and finds that 142 of them made their visit because of a coupon they'd received in the mail.
This means that 
95% confidence level
So
, z is the value of Z that has a p-value of
, so
.
The lower limit of this interval is:

The upper limit of this interval is:

The 95% confidence interval for the fraction of all shoppers during the year whose visit was because of a coupon they'd received in the mail is (0.2016, 0.2694).
Answer:
3. A; 4. C; 5. D; 6. D
Step-by-step explanation:
3. By Pythagorean theorem, x^2=100-64=36, x=6
4. By Pythagorean theorem, x^2=81-36=25, x=5
5. Since the triangle is an isosceles, the other side is 4, so the hypotenuse is 4
. (the ratio is 1:1:
by Pythagorean theorem)
6. Like Question #5, the ratio is 1:1:
since it is an isosceles triangle, the leg is 8.
There are 16 possible outcomes.
This is found by taking the number of possible outcomes for each toss, 2, and raising it to the 4th power (for 4 tosses):
2⁴ = 2*2*2*2 = 16