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:
x=4 and y=3
Step-by-step explanation:
put one of the equations in slope form and solve
We have been given a diagram. We are asked find the measure of arc EAB.
First of all, we will find the measure of arcs ED and CB using our given information.
We know that measure of an inscribed angle is half the measure of intercepted arc.
We can see that angle EBC is inscribed angle of arc EDC, so measure of arc EDC will be twice the measure of angle EBC.
Similarly, we will find the measure of arc DCB.
Therefore, the measure of arc EAB is 148 degrees and option C is the correct choice.
Answer:
Step-by-step explanation:
The directrix is a vertical line, so the parabola is horizontal. The focus lies to the left of the directrix, so the parabola opens to the left.
For a left-opening parabola:
x = a(y-k)²+h,
a < 0,
vertex (h,k)
focal length p = 1/|4a|
focus (h-p, k)
directrix: x=h+p
Apply your data
focus (1,-4)
directrix x=2
vertex (1.5,-4).
focal length p = 0.5
a = -1/|4p| = -½
x = -½(y-2)²+ ½
P = 2(L + W)
P = 200
L = W + 80
200 = 2(W + 80 + W)
200 = 2(2W + 80)
200 = 4W + 160
200 - 160 = 4W
40 = 4W
40/4 = W
10 = W.........the width is 10 yds
