Sam’s Music Store wanted to take a survey of the age range of people that visited the store. Over the course of a week, they ask
40 people their age as they walked in. Above is a box plot of the collected data. Answer the following questions about the box plot in relation to the problem.
How many customers were age 28 or below? Use a specific number, not a percentage.
How many customers were age 28 or below? Use a specific number, not a percentage.
1 answer:
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Here are the pictures of the steps I took when solving it as well as the answer to what X is
Answer:
The 90% confidence interval for the mean time required by all college graduates is between 5.36 years and 5.44 years.
Step-by-step explanation:
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.
The lower end of the interval is the sample mean subtracted by M. So it is 5.4 - 0.04 = 5.36 years.
The upper end of the interval is the sample mean added to M. So it is 5.4 + 0.04 = 5.44 years.
The 90% confidence interval for the mean time required by all college graduates is between 5.36 years and 5.44 years.