91影视

Compute a \(99\% \) \(CI\) for \({\mu _1} - {\mu _2}\)using the data in Exercise \(12\).

The accompanying data refers to concentration of the radioactive isotope strontium-90 in milk samples obtained from five randomly selected dairies in each of four different regions.

1 6.4 5.8 6.5 7.7 6.1

2 7.1 9.9 11.2 10.5 8.8

3 5.7 5.9 8.2 6.6 5.1

4 9.5 12.1 10.3 12.4 11.7

Test at level .10 to see whether true average strontium-90 concentration differs for at least two of the regions.

The article 鈥淧roduction of Gaseous Nitrogen in Human Steady-State Conditions鈥� (J. of Applied Physiology, 1972: 155鈥�159) reports the following observations on the amount of nitrogen expired (in liters) under four dietary regimens: (1) fasting, (2) 23% protein, (3) 32% protein, and (4) 67% protein. Use the Kruskal-Wallis test at level .05 to test equality of the corresponding \[{\mu _I}'s\].

1 4.079 4.859 3.540 5.047 3.298

2 4.368 5.668 3.572 5.848 3.802

3 4.169 5.709 4.416 5.666 4.123

4 4.928 5.608 4.940 5.291 4.674

1 4.679 2.870 4.648 3.847

2 4.844 3.578 5.393 4.374

3 5.059 4.403 4.496 4.688

4 5.038 4.905 5.208 4.806

The accompanying data on cortisol level was reported in the article 鈥淐ortisol, Cortisone, and 11-Deoxycortisol Levels in Human Umbilical and Maternal Plasma in Relation to the Onset of Labor鈥� (J. of Obstetric Gynaecology of the British Commonwealth, 1974: 737鈥�745). Experimental subjects were pregnant women whose babies were delivered between 38 and 42 weeks gestation. Group 1 individuals elected to deliver by Caesarean section before labor onset, group 2 delivered by emergency Caesarean during induced labor, and group 3 individuals experienced spontaneous labor. Use the Kruskal-Wallis test at level .05 to test for equality of the three population means.

Group 1 262 307 211 323 452 339

304 154 287 356

Group 2 467 501 455 355 468 362

Group 3 343 772 207 1048 838 687

In a test to determine whether soil pretreated with small amounts of Basic-H makes the soil more permeable to water, soil samples were divided into blocks, and each block received each of the four treatments under study. The treatments were (A) water with .001% Basic-H flooded on control soil, (B) water without Basic-H on control soil, (C) water with Basic-H flooded on soil pretreated with Basic-H, and (D) water without Basic-H on soil pretreated with Basic-H. Test at level .01 to see whether there are any effects due to the different treatments.

In an experiment to study the way in which different anesthetics affect plasma epinephrine concentration, ten dogs were selected and concentration was measured while they were under the influence of the anesthetics isoflurane, halothane, and cyclopropane (鈥淪ympathoadrenal and Hemodynamic Effects of Isoflurane, Halothane, and Cyclopropane in Dogs,鈥� Anesthesiology, 1974: 465鈥�470). Test at level .05 to see whether there is an anesthetic effect on concentration

The article 鈥淓ffects of a Rice-Rich Versus Potato-Rich Diet on Glucose, Lipoprotein, and Cholesterol Metabolism in Noninsulin-Dependent Diabetics鈥� (Amer. J. of Clinical Nutr., 1984: 598鈥�606) gives the accompanying data on cholesterol synthesis rate for eight diabetic subjects. Subjects were fed a standardized diet with potato or rice as the major carbohydrate source. Participants received both diets for specified periods of time, with cholesterol-synthesis rate (mmol/day) measured at the end of each dietary period. The analysis presented in this article used a distribution-free test. Use such a test with significance level .05 to determine whether the true mean cholesterol-synthesis rate differs significantly for the two sources of carbohydrates.

High-pressure sales tactics or door-to-door salespeople can be quite offensive. Many people succumb to such tactics, sign a purchase agreement, and later regret their actions. In the mid-1970s, the Federal Trade Commission implemented regulations clarifying and extending the rights of purchasers to cancel such agreements. The accompanying data is a subset of that given in the article 鈥淓valuating the FTC Cooling-Off Rule鈥� (J. of Consumer Affairs, 1977: 101鈥�106). Individual observations are cancellation rates for each of nine sales people during each of 4 years. Use an appropriate test at level .05 to see whether true average cancellation rate depends on the year.

Here again is the data on expense ratio (%) for a sample of 20 large cap blended mutual funds introduced in Exercise 1.53:

1.03 1.23 1.10 1.64 1.30 1.27 1.25

.78 1.05 .64 .94 .86 1.05 .75

.09 0.79 1.61 1.26 .93 .84

A normal probability plot shows a distinctly nonlinear pattern, primarily because of the single outlier on each end of the data. But a dotplot and boxplot exhibit a reasonable amount of symmetry. Assuming a symmetric population distribution, does the data provide compelling evidence for concluding that the population mean expense ratio exceeds 1%? Use the Wilcoxon test at significance level .1. (Note: The mean expense ratio for the population of all 825 such funds is actually 1.08.)

The given data on phosphorus concentration in topsoil for four different soil treatments appeared in the article 鈥淔ertilisers for Lotus and Clover Establishment on a Sequence of Acid Soils on the East Otago Uplands鈥� (N. Zeal. J. of Exptl. Ag., 1984: 119鈥�129). Use a distributionfree procedure to test the null hypothesis of no difference in true mean phosphorus concentration (mg/g) for the four soil treatments.

I 8.1 5.9 7.0 8.0 9.0

II 11.5 10.9 12.1 10.3 11.9

III 15.3 17.4 16.4 15.8 16.0

IV 23.0 33.0 28.4 24.6 27.7