comparison of the precisions of two machines developed for extracting juice from oranges is to be made using the following data. Is there sufficient evidence to indicate that there is a difference in the precision of the two machines at the 5% level of significance? Machine A Machine B s2 = 1.4 ounces2 s2 = 3.1 ounces2 n=25 n=20

A study was conducted to investigate drinking problems among college students. In 1983, a group of students were asked whether they had ever driven an automobile while drinking. In 1987, after the legal drinking age was raised, a different group of college students was asked the same question. The results are as shown in the table below. Test to compare the proportions of students with a drinking problem at 0.05 level of significance, 1987 versus 1983; and provide the chi-squared statistic value below (in 2 decimal places). Year Drove while drinking Yes No 1983 1,258 1,355 1987 994 1,643

A psychologist was looking at the effects of an intervention on depression levels. Three groups were used: waiting list control, treatment and post treatment (a group who had had the treatment 6 months before). The change in depression levels over the time of the treatment were recorded (although bear in mind only the treatment group actually got any treatment during this time). The SPSS output is below; based on this output what should the researcher conclude?

Explain the findings of this crosstab, including a description of the table, a calculation of the epsilons, and a discussion of the 10% rule. Explain what the output of the measure of association means in terms of strength and direction of the relationship. Interpret Proportional Reduction of Error (PRE) using the following statement: Knowing the IV will reduce error in predicting the DV by *%.

Which of the following would probably NOT be a potential “cure” for non-normal residuals? Select one: a. Transforming two explanatory variables into a ratio. b. Removing large negative residuals. c. Removing large positive residuals. d. Using a procedure for estimation and inference which did not assume normality.

4. A new method for cholesterol utilizing 4 - aminoantipyrine was evaluated in the laboratory. The procedure was run in on 20 separate days. The following values are given: Mean = 150 mg/dl Sum of the squared difference from the mean is 3600 Calculate the SD.

J In-shop othesis test for the difference between two population proportions 02562 2600368.qx3zqy7 Jump to level 1 The manager of a coffee shop is trying to determine if drive-through customers buy fewer items than customers who come into the shop. The manager randomly samples both populations and calculates the proportion of customers in each that buy three or more items. The results of the data collected are shown below. What are the population parameters? Y Pick Drive-through Successes 27 Successes What is the level of significance? Ex: 0.12 Observations 76 Observations 41 119 0.345 p-hat_1 0.355 p-hat_2 What is the null hypothesis Ho? Pick Confidence Level 0.1429 What is the alternative hypothesis Ha? Pick p-value Should Ho be rejected or does Ho fail to be rejected? Pick What conclusion can be drawn from the data? Pick evidence exists to support the claim that drive-through customers buy fewer items than in-shop customers. 2 p W

Data consistent with summary quantities in the article "Effects of Fast-Food Consumption on Energy Intake and Diet Quality Among Children" on total calorie consumption on a particular day are given for a sample of children who did not eat fast food on that day and for a sample of children who did eat fast food on that day. Assume that it is reasonable to regard these samples as representative of the population of children in the United States. No Fast Food 2342 1929 1020 1741 1480 2064 2154 1992 1863 1788 1776 1838 1659 1517 2680 Fast Food 2522 1757 933 2327 2433 2266 2525 1194 889 1510 874 2206 1810 1249 2116 (a) Use the given information to estimate the mean calorie intake for children in the United States on a day when no fast food is consumed. (Give the answer to one decimal place.) 1856.2 (b) Use the given information to estimate the mean calorie intake for children in the United States on a day when fast food is consumed. (Give the answer to one decimal place.) 1774.1 (c) Use the…

Benign prostatic hyperplasia is a non-cancerous enlargement of the prostate gland that adversely affects the quality of life of millions of men. A study of a minimally invasive procedure for the treatment of this condition looked at pretreatment Quality of Life (QOL Base) and Quality of Life (QOL 3Mo) after 3 months on treatment. Quality of Life was rated using an ordinal scale of 0 to 6, where 0 is "Delighted" and 6 is "Terrible" Create a "Delta" column depicting the Difference between the Base and 3-month ratings Find the Mean of the Differences, Standard Deviation and Standard Error for the Delta values Is there a Significant Difference in Quality of Life 3 months after treatment? Find the tsat value and the corresponding p-value boundaries using Table C

Which best illustrates the distinction between statistical significance and practical importance?     Multiple Choice   "This year, 360 of 440 statistics students at Oxnard Technical College rented their textbooks, compared with 110 of 330 students last year. This is a significant increase."     "Our new manufacturing technique has increased the life of the 80 GB USB AsimoDrive external hard disk significantly, from 240,000 hours to 250,000 hours."     "In 50,000 births, the new vaccine reduced the incidence of infant mortality in Morrovia significantly from 14.2 deaths per 1000 births to 10.3 deaths per 1000 births."     "The new Sky Penetrator IV business jet’s cruising range has increased significantly from 3,975 miles to 4,000 miles."