Answer:
She subtracted 7x instead of dividing it. Personally, i wouldn't have done that. I would subtract the 14 first, then divide.
The formula for the circumference of a circle is C = 2pi*r, where r is the radius. Here, 7850 units = C = 2pi*r.
Dividing 7850 units by 2pi, we get
7850 units
r = ----------------- = 1249 units (to the nearest unit)
2pi
Answer:
1800(5/6)^t
Step-by-step explanation:
I don't see any answer choices, but this would be another form if it is listed. The negative exponent means that you get the reciprocal of the fraction (in this case 1.2). This turns 1.2 into (1/1.2), which is equivalent to 5/6.
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).