Expert Answers

1 A health inspector at a restaurant will enter the kitchen and choose 5 stations to inspect from a predetermined list of 15 stations present in most restaurant kitchens.
a. How many different sets of 5 stations exist?

b. If all sets are equally likely, what is the probability of each set?

c. If the inspector were instead to randomly select 13 stations to inspect, how many different sets of 13 stations would exist?

d. If all sets were equally likely, what is the probability of each set?

3.When the owner of a small business reviews her list of contracts for 2011, she finds that 35% of the contracts were from clients she met at a large conference at the end of 2010. Answer the following questions about this situation.

A. Was this measurement obtained by a sample or a census? What words in the description of the situation make you confident that your answer is correct?

B. Should the owner have taken into account some measure of reliability associated with the value 35%.

5. Since careful records have begun being kept in January, Eric’s small business has delivered the following quantities of flowers throughout town

January  February   March   April  May  June  July     August
Small Bouquets       85           34              26          24      43     29     30        19
Large Bouquets       23           64              27          18      33     23     20        13

Assuming the data is normally distributed construct two separate 90% confidence intervals one for the number of deliveries of small bouquets in September and one for the number of large bouquets in September.

6. If the vertical axis of a graph is unusually tall, how might that misrepresent the data or mislead the viewer?

7. A quality control analyst measures the number of hours a patient in a low-risk condition waits for car at the emergency room of a small hospital. The following data are obtained for 20 patients.

2.26, 2.01, 3.0, 1.22, 1.92, 1.79, 0.78, 1.89, 0.71, 1.58
2.02, 2.77, 2.87, 0.51, 0.74, 1.95, 2.76, 2.61, 3.54, 2.95

a. Compute the sample mean, sample median, and range of data

b. Compute the sample standard deviation and sample variance

8. A quality control experiment is to be done on a machine that fills tubes with toothpaste. Its specifications require that it fill tubes with 4.7 oz. A random sample of 40 tubes filled by machine is taken and each tube is weighed. The resulting data are below, with the weight of the tube already having been subtracted from each. Perform a hypothesis test at the 90% confidence level to determine if the machine is performing according to specifications.

4.66, 4.61, 4.71, 4.63, 4.70, 4.62, 4.63, 4.61, 4.70, 4.56
4.60, 4.66, 4.68, 4.57, 4.67, 4.72, 4.67, 4.64, 4.66, 4.75
4.69, 4.64, 4.67, 4.65, 4.69, 4.65, 4.75, 4.53, 4.57, 4.74
4.68, 4.67, 4.66, 4.68, 4.64, 4.65, 4.64, 4.80, 4.71, 4.69