Working with inference.

What is the difference in the average daily hotel room rates between Minneapolis and New Orleans? Suppose we want to estimate this difference by taking hotel rate samples from each city and using a 98% confidence level. The data for such a study follows. Use this data to produce an interval estimate and also a point estimate for the mean difference in the hotel rates for the two cities. Assume the population variances are approximately equal and hotel rates in any given city is normally distributed. MINNEAPOLIS---NEW ORLEANS nm = 22--------nno = 20 Xm = $112------Xno = $122 Sm = $11-------Sno = $12

Inference

Various types of retail outlets sell toys during the holiday season. Among them are specialty toy stores, the large discount toy stores, and other retailers that carry toys as only one part of their stock of goods. Is there any difference in the dollar amount of a customer purchase between a large discount toy store and a specialty toy store if they carry relatively comparable types of toys? Suppose in December a random sample of 60 sales slips is selected from a large discount toy outlet and a random sample of 40 sales slips is selected from a specialty toy store. The data gathered from these samples follow. LARGE DISCOUNT TOY STORE SPECIALTY TOY STORE X1 = $47.20 ... click for more

Probability

2. The probability that a person is immune to a certain disease is 0.40. a) What is the probability that 4 people will have the disease in a sample of 12 people b) Find the mean number of people who have immunity in a sample size of 12. c) Find the standard deviation for the same sample 3. If the capacities of the cranial cavities of a certain population are approximately normally distributed with a mean of 1400cc and a standard deviation of 125, find the probability that a randomly selected person from the given population will have a cranial capacity greater than 1450cc. 4. IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. In a random sampl... click for more

Statistics

5. Human body temperatures are normally distributed with a mean of 98.6 degrees F and a standard deviation of 0.72 deg. F. Find the temperature that separates the top 7% from the bottom 93%. 6. In a sample of 49 adolescents who served as the subjects in an immunologic study, one variable of interest was the diameter of skin test reaction to an antigen. The sample mean and sample standard deviation were 21 and 11 mm erythema, respectively. Can it be conducted from these data that the population mean is less than 30? Let alpha=0.05. Assume that the population standard deviation is 12.2 7. A test of abstract reasonign is given to a random sample of students before and after they complet... click for more

Hypothesis test using ANOVA, Chi-square

8.To examine the effect of pets in stressful situations researchers recruited 45 women who said they were dog lovers. Fifteen of the subjects were randomly assigned to each of the 3 groups to do a stressful task alone with a good friend present, or with their dog present. (The stressful task was to count backwards by 13s or 17s). The subjects mean heart rate during the task is one measure of the effect of stress. The Minitab ANOVA output for the data is given below. MINITAB Analysis of Variance for rate Source DF SS MS F P group 2 2387.7 1193.8 14.08 0.000 Error 42 3561.3 84.8 Total 44 5949.0 Level N Mean StDev control 15 82.524 9.242 friend 15 91.325 9.970 pet 15 73.48... click for more