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).
Answer:
Step-by-step explanation:
8x + 15 = 24
8x = 9
x = 
Answer:
23/50, 0.46, and 46%
Step-by-step explanation:
This problem is stating that every fifty times you flip a coin you get 23 heads. Finding the fraction is simple, it would be 23/50 because it is expressing the probability. The problem clearly states that every 50 times you get 23 heads. To find the decimal, take the fraction, 23/50, and multiply the numerator and denominator by 2. you get 46/100 which is 0.46. A percent is just a fraction out of a 100 which would make the percent 46.
Option D:
Solution:
Given function:
To find the inverse of the function.
<u>Inverse of a function:</u>
<em>If a function f(x) is mapping x to y, then the inverse function of f(x) maps y back to x.</em>
Interchange the variables x and y.
Now, solve for y.
Multiply both sides by (y - 5).
Cancel the common factors, we get
Divide by x on both sides.
Add 5 on both sides.
To make the denominator same, multiply the 2nd term by 
.
Option D is the correct answer.
