7 1/12 - 2 3/4
First we have to change mixed numbers to improper fractions
7 1/12 = 7 x 12 + 1 = 85 85/12
2 3/4 = 2 x 4 + 3 = 11 11/4
85/12 - 11/4
Now we need to find the LCD (least common denominator) for 4 and 12
4, 8, 12
12
12 is our LCD, so it becomes our new denominator
85/12 would stay the same because the denominator wasn't changed but for 11/4 our new denominator is 12, so our fraction will change.
11/4 = 33/12
4 goes into 12, 3 times. What you do to the bottom, you do to the top.
3 x 11 = 33
3 x 4 = 12
So, our new fraction is 33/12. Now we subtract
85/12 - 33/12 = 52/12
Now we convert back to a mixed number
52 ÷ 12 = 4 4/12 reduce
4 1/3
Hope this helps.
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:

Step-by-step explanation:
Given:
Center of circle is at (5, -4).
A point on the circle is 
Equation of a circle with center
and radius 'r' is given as:

Here, 
Radius of a circle is equal to the distance of point on the circle from the center of the circle and is given using the distance formula for square of the distance as:
Using distance formula for the points (5, -4) and (-3, 2), we get

Therefore, the equation of the circle is:

Now, rewriting it in the form asked in the question, we get

You just add the values for volunteers that worked 16-20 hours and 21-25 hours which would be 50 + 10 = 60. So the total number of volunteers that workers more than 15 hours is 60.
The answer to that is 2/5