Statistics - Chapter 10 Questions

Chapter 10 Questions

The MacBurger restaurant chain claims that the mean waiting time of customers is 3 minutes with a population standard deviation of 1 minute. The quality assurance department found in a sample of 50 customers at the Warren Road MacBurger that the mean waiting time was 2.75 minutes. At the .05 significance level, could one say that the mean waiting time is less than 3 minutes?
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At the time she was hired as a server at Chili's, Beth Smith was told, "You can average more than $80 a day in tips", assume the standard deviation of the population distribution is $3.24. Over the first 35 days she was employed at the restaurant, the mean daily amount of her tips was $84.85. At the .01 significance level, can Beth conclude that she is earning an average of more than $80 in tips?

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Most air travelers now use e-tickets. Electronic ticketing allows passengers to not worry about a paper ticket, and it costs the airline companies less to handle than paper ticketing. In recent times airlines have received complaints from passengers regarding their e-tickets, particularly when connecting flights and a change of airlines were involved. To investigate the problem an independent watchdog agency contacted a random sample of 20 airports and collect information on the number of complaints the airport had with e-tickets for the month of March.

14 14 16 12 12 14 13 16 15 14
12 15 15 14 13 13 12 13 10 13

At the .05 significance level can the watchdog agency conclude the mean number of complaints per airport is less than 15 per month?

What assumption is necessary before conducting a test of hypothesis?

Plot the number of complaints per airport in a frequency distribution of a dot plt. Is it reasonable to conclude that the population follows a normal distribution?

Conduct a test of hypotheses and interpret the results.