4. So
1 answer:
Answer:
Step-by-step explanation:
The monthly plan costs starts at $29.95, so we're not changing that.
For each monthly plan, we have to pay a tax of $2.95, so we're not changing that.
If we go over 1,000 minutes, we have to pay $0.05 for every minute we go over, and with the fact that represents each minute over 1,000, we're going to have to represent minutes over 1,000 as
in our equation.
Set up your equation:
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To find Jenny's age as a percentage of her great grandmother's age :
Answer:
a. The 95% confidence interval for the proportion of all adult Americans who would give themselves a grade of A or B on their financial knowledge of personal finance is (0.54, 0.588). This means that we are 95% sure that the true proportion of all adult Americans who would give themselves a grade of A or B on their financial knowledge of personal finance is between these two bounds.
b. Because this confidence interval is entirely above 0.5, the interval is consistent with the statement that a majority of adult Americans would give themselves a grade of A or B.
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 .
Sample of 1,664 adult Americans, 939 people in the sample would have given themselves a grade of A or B in personal finance.
This means 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 for the proportion of all adult Americans who would give themselves a grade of A or B on their financial knowledge of personal finance is (0.54, 0.588). This means that we are 95% sure that the true proportion of all adult Americans who would give themselves a grade of A or B on their financial knowledge of personal finance is between these two bounds.
(b) Is the confidence interval from part (a) consistent with the statement that a majority of adult Americans would give themselves a grade of A or B?
Yes, because the confidence interval is entirely above 0.5.
Because this confidence interval is entirely above 0.5, the interval is consistent with the statement that a majority of adult Americans would give themselves a grade of A or B.