CASE 1 : Scarr & Crick explored the incidence of altrusim in people with different blood groups. Among people with O+ blood group 50 believed in ethical treatment of animals, 20 in philanthropy, and 30 in reciprocity. Among people with AB+ blood group 30 believed in ethical treatment, 45 in philanthropy and 25 in reciprocity.

1. What are the researchers’ Null & Research hypotheses? [6 points]
2. What statistic will you use? Set up the test and calculate the statistic. [10 points]
3. What is the critical value (from table, for = 0.05)? What are your df? What are your conclusions? [4 points]

Total: 20 points

CASE 2 : The following problems use the binomial [5 point each]:

1. At a certain intersection, the light for eastbound traffic is red for 15 seconds, yellow for 5 seconds, and green for 30 seconds. Find the probability that out of the next eight eastbound cars that arrive randomly at the light, exactly three will be stopped by a red light.
2. According to historical weather data, 73% of the days in March are rainy in Seattle. If you go to Seattle for four days in March, what is the probability that all four days will be rainy?
3. In a certain city, 65% of all dog bites lead to rabies. If 20 people in that city are bitten by dogs in a given week, what is the probability that no more than 17 of them will get rabies?
4. For the city in question (iii), what is the mean number of people that contract rabies in a week when 25 people are bitten? What is the standard deviation?

Total: 20 points

CASE 3 : Researchers want to examine the effect of perceived control on health complaints of geriatric patients in a long-term care facility. Twenty patients are randomly selected. Half are given a plant to care for and half are given a plant but the staff take care of it. The number of health complaints are recorded for each patient over the following 7 days.

Control over Plant No Control over Plant

23 35

12 21

6 26

15 24

18 17

5 23

21 37

18 22

34 16

10 38

1. What are the Null and Alternate hypotheses? [5 points].
2. Compute the appropriate statistic and give your conclusions. [5 points].
3. What is the effect size and power for this data? What is the probability of a Type I and a Type II error in this situation? Which is greater? Explain your answer [10 points].

Total: 20 points

CASE 4 : Researchers at Vanderbilt’s Virtual Reality lab have looked at people’s angular errors when they walk in a virtual environment (VE) and real environment (RE). Here is a portion of the data that the researchers obtained when they tested people in 3 different virtual "rooms," [VE data presented in the top half] and 3 corresponding real rooms [RE data presented in the lower half]. The researchers wanted to see whether the rooms differed in the errors participants produced, and in the response times in each room.

1. Give the Null Hypothesis and Alternate Hypothesis. [10 points]
2. Do the appropriate test and give the summary table. [25 points].
3. What are your conclusions? [5 points]

Total points = 40

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Solution: The downloadable solution consists of 12 pages, 1022 words and 2 charts.
Deliverable: Word Document