9.  A sample of students at Santa Fe College who said they d…

9.  A sample of students at Santa Fe College who said they drank alcohol in the past 30 days were asked how many alcoholic drinks they had, per occasion.  The data (in number of drinks) is as follows:  2, 4, 4, 11, 3, 1, 2, 1, 7, 5, 4, 6. (c)  What are the measurement units for the standard deviation?

7. Bear gallbladder is used in Chinese medicine to treat inf…

7. Bear gallbladder is used in Chinese medicine to treat inflammation.  Due to the difficulty of obtaining bear gallbladder, Chinese medical researchers are searching for a more readily available source.  A study in the Journal of Ethnopharmacology (June 1995) examined pig gallbladder as an effective substitute for bear gallbladder.  Twenty male mice were divided randomly into two groups:  10 were given a dosage bear bile and 10 were given a dosage of pig bile.  All the mice then received an injection of croton oil in the left ear lobe to induce inflammation.  Four hours later, both the left and right ear lobes were weighed, with the difference (in milligrams) representing the degree of swelling.  Summary statistics are provided below: Bear Bile:       n = 10       sample mean = 9.19       s = 4.17 Pig Bile:       n = 10       sample mean = 9.71       s = 3.33 Assume that the populations of the difference of swelling for bear bile and pig bile ears are normally distributed.  Do the data show that the mean degree of swelling of mice treated with bear bile is significantly less than the mean degree of swelling of mice treated with pig bile?  (While answering the following sub-parts of this question, you will be including the null and alternative hypothesis, the test statistic, the p-value (a visualization and an interpretation), your statistical decision, and your conclusion in the context of the problem.) (c) Interpret the p-value for Step 3 of the hypothesis test.

6.  Disney World’s Animal Kingdom is a family theme park in…

6.  Disney World’s Animal Kingdom is a family theme park in Orlando, Florida. One of its longest rides, “Kilimanjaro Safaris,” has a ride time that is normally distributed with a mean of μ = 14 minutes and a standard deviation of σ = 3 minutes.  If the ride lasts more than 19 minutes, it is considered too long and the manager must decrease the ride time. (b) What is the z-score that you calculated and then used to find the probability in part a?

7.  Students in an experimental psychology class use various…

7.  Students in an experimental psychology class use various techniques to train a rat to move through a maze.  At the end of the class, each student’s rat is timed through the maze.  Assume the distribution of maze completion times is mound shaped with a mean of 4.74 minutes and a standard deviation of 1.20 minutes. (a) Describe the maze time distribution.

5. A survey of automobile ownership was conducted of 200 fam…

5. A survey of automobile ownership was conducted of 200 families in Houston.  The results of the study showing ownership of automobiles of United States and foreign manufactures are summarized as follows: Own a U.S.  car Don’t own a U.S. car Totals Own a foreign car 30 10 40 Don’t own a foreign car 150 10 160 Totals 180 20 200 (b) What is the probability that a family owns a U.S. and foreign car?