b. Based on the data do the students have a legitimate complaint about the machine not
giving them enough coffee on average?
c. If the students had taken a random sample of 100 cups (all other info staying the same)
how would this affect the margin of error?
d. What sample size is needed if the students wanted the margin of error to be at most .02
ounces per cup?
3. To estimate the number of visitors per month to the John F. Kennedy Library, the
number of visitors was recorded for randomly selected months. Descriptive statistics on
the sample data are shown below. Assume standard deviation for number of visitors stays
at 35,000 people.
Descriptive Statistics: Visitors
Total
Variable
Count
Mean
Visitors
36
250926
a. Use the given information to estimate the average number of visitors to the JFK
library.
b. Using your answer to part a, what would be an unusually average for a given year?
What would be an unusually low average number of visitors for a given year? Why?
2
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View Full Document4. A group of randomly selected 50 sales representatives from a company had an average
sales of $107.5 million this year. (Assume the standard deviation of sales is stable at
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 Fall '11
 Johnson
 Statistics, Normal Distribution, Standard Deviation, average number, John F. Kennedy Library

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