For $7.52, you purchased 8 pens and highlighters form a local bookstore. Each highlighter cost $1.09 and each pen cost $.69. Wri
te a system of equations that can be used to find how many pens you bought.
1 answer:
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Answer:
The margin of error for the confidence interval is of 0.25 minutes.
Step-by-step explanation:
With what we are given, the only thing that this question can be asked is the margin of error for the confidence interval of the mean duration of telephone calls directed by a local telephone company.
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
So it is z with a pvalue of , so
Now, find the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
Using what we are given:
The margin of error for the confidence interval is of 0.25 minutes.