..Answer:
Step-by-step explanation:
...
Answer:
see explanation
Step-by-step explanation:
Using the trigonometric identity
sin²x + cos²x = 1
Consider the left side
2cos²A - 1 ← replace 1 by sin²A + cos²A
= 2cos²A - ( sin²A + cos²A)
= 2cos²A - sin²A - cos²A
= cos²A - sin²A = right side ⇒ verified
Answer:
22
Step-by-step explanation:
Circumference = diameter * pi = 22 * pi
The angle should not change. 35 degrees
Answer:
This means that the first interval, with 9000 viewers, is 3 times as narrower as the second interval, with 1000 viewers.
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
.
The width of the interval is:

In this sample:
Two 90% intervals, with different lenghts. So both have the same values for z an 
Interval A:
9000 viewers.
So the width is

Interval B:
100 viewers
So the width is

Relationship between the widths:

This means that the first interval, with 9000 viewers, is 3 times as narrower as the second interval, with 1000 viewers.