BST322

Q:  What is the probability of rolling a four in the gambling dice game of craps (given two six sided dice)? What is the probability that a player can roll a four 3 times in a row (assume that rolling the dice each time does not affect the outcome of the next roll)? 

Q:  Population A and Population B both have a mean height of 70.0 inches with an SD of 6.0. A random sample of 30 people is picked from population A, and random sample of 50 people is selected from Population B. Which sample mean will probably yield a more accurate estimate of its population mean? Why? 

Q: Suppose we obtained data on vein size after application of a nitroglycerin ointment in a sample of 50 patients. The mean vein size is found to be 8.7mm with an SD of 2.1. Using a t distribution table, what are the confidence limits for a 95% confidence interval? For a 99% confidence interval?

Q: For which of the following situations is the independent groups t-test appropriate (if inappropriate, why?):

a. The independent variable is infant birth weight at one week (normal vs high); the dependent variable is resting heart rate.

b. The independent variable is radiation treatment on throat cancer patients (after a low dose and then a high dose treatment); the dependent variable is white blood cell count.

c. The IV is infant birth weight (low vs normal vs high); the DV is number of days absent from school in first grade.

d. The IV is gender (male vs female); the DV is compliance vs noncompliance with a medication regimen.

e. The independent variable is married status (single vs married); the dependent variable is happiness measured on a scale from 1 to 50 

Q: For which of the following situations is the dependent groups t-test appropriate (if not appropriate, why?)

a. The IV is presence or absence of conversation directed to comatose patients (same patients with and without conversation); the DV is the patients’ intracranial pressure.

b. The IV is birth type (home vs hospital); the DV is perceived functional ability of the patient 48 hours after surgery.

c. The IV is time since incarceration (1 months vs 3 months vs 6 months); the DV is body weight.

d. The IV is menopausal state (pre vs post) in the same women over time; the DV is attitudes toward menopause.

e. The IV is nap therapy for narcoleptics (same patients before vs after treatment); the DV is the type of nap they had the following week (had unplanned vs didn’t have unplanned nap). 

Q: Suppose we wanted to test the hypothesis that a control group of cancer patients (Group 1) would report higher mean pain ratings than an experimental group receiving special massage treatments (Group 2). Use the following information. Compute a t-statistic for independent groups:

mean group 1 = 78.1 SD21 = 42.1 n1 = 25

mean group 2 = 74.1 SD22 = 39.7 n2 = 25

Q: For each of the following situations, indicate whether ANOVA is appropriate; if not appropriate, the reason why not; and, if appropriate, the type of ANOVA that would be used (i.e., one-way, repeated measures, etc.)

a. The IVs are ethnicity (Asian, White, African American, Hispanic) and gender (male vs female); the DV is serum cholesterol levels.

b. The IV is smoking status – smokers vs non-smokers; the DV is health-related hardiness as measured on a 20-item scale.

c. The IV is maternal breast feeding status (breastfeeds daily vs breastfeeds at least 1-3 times/week vs doesn’t breastfeed); the DV is maternal bonding with infant, as measured on a 20-item self-report scale.

d. The IV is treatment group for patients with drug-induced shivering (extremity wraps vs high room temp vs normal room temp without wraps) different patients used for each treatment; the DV is myocardial oxygen consumption (measured in ml O2/min per 100g of tissue).

e. The IV is length of gestation (preterm vs term vs postterm) using the same multiple birth mothers over time; the DV is blood pressure 10 minutes post delivery. 

Q: For each of the following F values, indicate whether the F is statistically significant at the specified alpha level:

a. F = 4.80, df = 4, 40 α = 0.01

b. F = 5.02, df = 3, 60, α = 0.001

c. F = 3.45, df = 3, 27, α = 0.05

d. F = 1.99, df = 2, 150, α = 0.05

e. F = 3.09, df = 2, 250, α = 0.05