Mathematical Statistics with Applications
7th Edition
ISBN: 9780495110811
Author: Dennis Wackerly, William Mendenhall, Richard L. Scheaffer
Publisher: Cengage Learning
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Chapter 7.2, Problem 16E
Referring to Exercise 7.13, suppose that the effects of copper on a second species (say, species B) of fish show the variance of ln(LC50) measurements to be .8. If the population means of ln(LC50) for the two species are equal, find the
The Environmental Protection Agency is concerned with the problem of setting criteria for the amounts of certain toxic chemicals to be allowed in freshwater lakes and rivers. A common measure of toxicity for any pollutant is the concentration of the pollutant that will kill half of the test species in a given amount of time (usually 96 hours for fish species). This measure is called LC50 (lethal concentration killing 50% of the test species). In many studies, the values contained in the natural logarithm of LC50 measurements are
Studies of the effects of copper on a certain species of fish (say, species A) show the variance of ln(LC50) measurements to be around .4 with concentration measurements in milligrams per liter. If n = 10 studies on LC50 for copper are to be completed, find the probability that the sample mean of ln(LC50) will differ from the true population mean by no more than .5.
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Question 2
Parts manufactured by an injection molding process are subjected to a compressive strength test. Twenty samples
of five parts each are collected, and the compressive strengths (in psi) are shown in Table 2.
Table 2: Strength Data for Question 2
Sample Number
x1
x2
23
x4
x5
R
1
83.0
2
88.6 78.3 78.8
3
85.7
75.8
84.3
81.2 78.7 75.7 77.0
71.0 84.2
81.0
79.1
7.3
80.2 17.6
75.2
80.4
10.4
4
80.8
74.4
82.5
74.1 75.7 77.5
8.4
5
83.4
78.4
82.6 78.2
78.9
80.3
5.2
File Preview
6
75.3
79.9
87.3 89.7
81.8
82.8
14.5
7
74.5
78.0 80.8
73.4
79.7
77.3
7.4
8
79.2
84.4 81.5 86.0
74.5
81.1
11.4
9
80.5
86.2
76.2 64.1
80.2
81.4
9.9
10
75.7
75.2
71.1 82.1
74.3
75.7
10.9
11
80.0 81.5
78.4 73.8
78.1
78.4
7.7
12
80.6
81.8
79.3
73.8
81.7 79.4
8.0
13
82.7
81.3
79.1
82.0 79.5 80.9
3.6
14
79.2
74.9
78.6 77.7
75.3
77.1
4.3
15
85.5 82.1
82.8 73.4
71.7
79.1
13.8
16
78.8 79.6
80.2 79.1
80.8 79.7
2.0
17
82.1
78.2
18
84.5
76.9
75.5
83.5 81.2
19
79.0 77.8
20
84.5
73.1
78.2 82.1
79.2 81.1 7.6
81.2 84.4 81.6 80.8…
Name:
Lab Time:
Quiz 7 & 8 (Take Home) - due Wednesday, Feb. 26
Contingency Analysis (Ch. 9)
In lab 5, part 3, you will create a mosaic plot and conducted a chi-square contingency test to
evaluate whether elderly patients who did not stop walking to talk (vs. those who did stop)
were more likely to suffer a fall in the next six months. I have tabulated the data below.
Answer the questions below. Please show your calculations on this or a separate sheet.
Did not stop walking to talk
Stopped walking to talk Totals
Suffered a fall
Did not suffer a fall
Totals
12
11
23
2
35
37
14
14
46
60
Quiz 7:
1. (2 pts) Compute the odds of falling for each group. Compute the odds ratio for those
who did not stop walking vs. those who did stop walking. Interpret your result verbally.
Solve please and thank you!
Chapter 7 Solutions
Mathematical Statistics with Applications
Ch. 7.2 - Refer to Example 7.2. The amount of fill dispensed...Ch. 7.2 - Refer to Exercise 7.9. Assume now that the amount...Ch. 7.2 - A forester studying the effects of fertilization...Ch. 7.2 - Suppose the forester in Exercise 7.11 would like...Ch. 7.2 - The Environmental Protection Agency is concerned...Ch. 7.2 - If in Exercise 7.13 we want the sample mean to...Ch. 7.2 - Suppose that X1, X2,Xm and Y1, Y2,Yn are...Ch. 7.2 - Referring to Exercise 7.13, suppose that the...Ch. 7.2 - Applet Exercise Refer to Example 7.4. Use the...Ch. 7.2 - Applet Exercise Refer to Example 7.5. If 2 = 1 and...
Ch. 7.2 - Ammeters produced by a manufacturer are marketed...Ch. 7.2 - a If U has a 2 distribution with v df, find E(U)...Ch. 7.2 - Refer to Exercise 7.13. Suppose that n = 20...Ch. 7.2 - Prob. 22ECh. 7.2 - Applet Exercise a Use the applet Chi-Square...Ch. 7.2 - Applet Exercise Refer to Example 7.6. Suppose that...Ch. 7.2 - Applet Exercise Suppose that T is a t-distributed...Ch. 7.2 - Refer to Exercise 7.11. Suppose that in the forest...Ch. 7.2 - Applet Exercise Refer to Example 7.7. If we take...Ch. 7.2 - Applet Exercise Suppose that Y has an F...Ch. 7.2 - If Y is a random variable that has an F...Ch. 7.2 - Suppose that Z has a standard normal distribution...Ch. 7.2 - a Use Table 7, Appendix 3, to find F.01 for...Ch. 7.2 - Applet Exercise a Find t.05 for a t-distributed...Ch. 7.2 - Prob. 33ECh. 7.2 - Suppose that W1 and W2 are independent...Ch. 7.2 - Prob. 35ECh. 7.2 - Let S12 denote the sample variance for a random...Ch. 7.2 - Let Y1, Y2,,Y5 be a random sample of size 5 from a...Ch. 7.2 - Suppose that Y1, Y2,,Y5, Y6, Y,W, and U are as...Ch. 7.2 - Prob. 39ECh. 7.3 - The fracture strength of tempered glass averages...Ch. 7.3 - An anthropologist wishes to estimate the average...Ch. 7.3 - Suppose that the anthropologist of Exercise 7.43...Ch. 7.3 - Workers employed in a large service industry have...Ch. 7.3 - The acidity of soils is measured by a quantity...Ch. 7.3 - Prob. 47ECh. 7.3 - Prob. 48ECh. 7.3 - The length of time required for the periodic...Ch. 7.3 - Shear strength measurements for spot welds have...Ch. 7.3 - Refer to Exercise 7.50. If the standard deviation...Ch. 7.3 - Resistors to be used in a circuit have average...Ch. 7.3 - One-hour carbon monoxide concentrations in air...Ch. 7.3 - Unaltered bitumens, as commonly found in leadzinc...Ch. 7.3 - The downtime per day for a computing facility has...Ch. 7.3 - Prob. 56ECh. 7.3 - Twenty-five heat lamps are connected in a...Ch. 7.3 - Prob. 58ECh. 7.3 - Prob. 59ECh. 7.3 - Prob. 60ECh. 7.3 - Refer to Exercise 7.60. Suppose that n1 = n2 = n,...Ch. 7.3 - Prob. 62ECh. 7.3 - Refer to Exercise 7.62. Find the number of...Ch. 7.5 - Applet Exercise Suppose that Y has a binomial...Ch. 7.5 - Prob. 66ECh. 7.5 - Prob. 67ECh. 7.5 - Prob. 70ECh. 7.5 - Prob. 71ECh. 7.5 - A machine is shut down for repairs if a random...Ch. 7.5 - An airline finds that 5% of the persons who make...Ch. 7.5 - According to a survey conducted by the American...Ch. 7.5 - A pollster believes that 20% of the voters in a...Ch. 7.5 - a Show that the variance of Y/n, where Y has a...Ch. 7.5 - The manager of a supermarket wants to obtain...Ch. 7.5 - If the supermarket manager (Exercise 7.77) samples...Ch. 7.5 - Suppose that a random sample of 25 items is...Ch. 7.5 - Prob. 80ECh. 7.5 - Prob. 81ECh. 7.5 - Prob. 82ECh. 7.5 - Prob. 84ECh. 7.5 - Prob. 85ECh. 7.5 - Prob. 86ECh. 7.5 - Prob. 87ECh. 7 - The efficiency (in lumens per watt) of light bulbs...Ch. 7 - Refer to Exercise 7.88. What should be the mean...Ch. 7 - Prob. 90SECh. 7 - A retail dealer sells three brands of automobiles....Ch. 7 - From each of two normal populations with identical...Ch. 7 - Prob. 93SECh. 7 - Prob. 94SECh. 7 - The coefficient of variation (CV) for a sample of...Ch. 7 - Prob. 96SECh. 7 - Prob. 97SECh. 7 - Prob. 100SECh. 7 - Prob. 101SECh. 7 - Prob. 102SECh. 7 - Prob. 103SECh. 7 - Prob. 104SECh. 7 - If the probability that a person will suffer an...
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Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.Similar questions
- 7. In a 2011 article, M. Radelet and G. Pierce reported a logistic prediction equation for the death penalty verdicts in North Carolina. Let Y denote whether a subject convicted of murder received the death penalty (1=yes), for the defendant's race h (h1, black; h = 2, white), victim's race i (i = 1, black; i = 2, white), and number of additional factors j (j = 0, 1, 2). For the model logit[P(Y = 1)] = a + ß₁₂ + By + B²², they reported = -5.26, D â BD = 0, BD = 0.17, BY = 0, BY = 0.91, B = 0, B = 2.02, B = 3.98. (a) Estimate the probability of receiving the death penalty for the group most likely to receive it. [4 pts] (b) If, instead, parameters used constraints 3D = BY = 35 = 0, report the esti- mates. [3 pts] h (c) If, instead, parameters used constraints Σ₁ = Σ₁ BY = Σ; B = 0, report the estimates. [3 pts] Hint the probabilities, odds and odds ratios do not change with constraints.arrow_forwardSolve please and thank you!arrow_forwardSolve please and thank you!arrow_forward
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