Answer:
The 95% confidence interval estimate for the true proportion of adults residents of this city who have cell phones is (0.81, 0.874).
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 zscore that has a pvalue of
.
For this problem, we have that:

95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
The lower limit of this interval is:

The upper limit of this interval is:

The 95% confidence interval estimate for the true proportion of adults residents of this city who have cell phones is (0.81, 0.874).
I hope this helps you
5=7x+0.1+10x-0.2
17x=5.1
x=5.1/17
x=3/10
x=0.3
Answer:
B
Step-by-step explanation:
First, let's rearrange the given equation into something more recognizable. If we add 13 to both sides, we now have the polynomial
. We can now use the quadratic formula to solve.
Remember that the quadratic formula is

Substitute the numbers from the equation into the formula.

Simplify:


Here, I'm going to assume that there was a mistype in option B because if we divide out the 2 we end up with
.
Hope this helps!
Answer:
<WSN=80
Step-by-step explanation:
arc WN = 160
<wsn= 1/2 of arc WN