Introductory Statistics (10th Edition)
10th Edition
ISBN: 9780321989178
Author: Neil A. Weiss
Publisher: PEARSON
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Chapter 11.1, Problem 38E
Dexamethasone and IQ. In the paper “Outcomes at School Age After Postnatal Dexamethasone Therapy for Lung Disease of Prematurity” (New England Journal of Medicine, Vol. 350, No. 13, pp. 1304–1313), T. Yeh et al. studied the outcomes at school age in children who had participated in a double-blind, placebo-controlled trial of early postnatal dexamethasone therapy for the prevention of chronic lung disease of prematurity. All of the infants in the study had had severe respiratory distress syndrome requiring mechanical ventilation shortly after birth. On the WeissStats site, we provide the school-age IQs of the 74 children in the control group, based on the study results. Use the technology of your choice to do the following.
- a. Obtain a normal
probability plot, boxplot, histogram, and stem-and-leaf diagram of the data. - b. Based on your results from part (a), can you reasonably apply one-standard-deviation χ2-procedures to the data? Explain your reasoning.
- c. Overall, IQs of school-age children have a standard deviation of 16. At the 1% significance level, do the data provide sufficient evidence to conclude that IQs of school-age children in similar postnatal circumstances as those in the control group of this study have a smaller standard deviation than that of school-age children in general?
- d. Find and interpret a 99% confidence interval for the standard deviation of IQs of all school-age children in similar postnatal circumstances as those in the control group of this study.
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Examine the Variables: Carefully review and note the names of all variables in the dataset. Examples of these variables include:
Mileage (mpg)
Number of Cylinders (cyl)
Displacement (disp)
Horsepower (hp)
Research: Google to understand these variables.
Statistical Analysis: Select mpg variable, and perform the following statistical tests. Once you are done with these tests using mpg variable, repeat the same with hp
Mean
Median
First Quartile (Q1)
Second Quartile (Q2)
Third Quartile (Q3)
Fourth Quartile (Q4)
10th Percentile
70th Percentile
Skewness
Kurtosis
Document Your Results:
In RStudio: Before running each statistical test, provide a heading in the format shown at the bottom. “# Mean of mileage – Your name’s command”
In Microsoft Word: Once you've completed all tests, take a screenshot of your results in RStudio and paste it into a Microsoft Word document. Make sure that snapshots are very clear. You will need multiple snapshots. Also transfer these results to the…
Examine the Variables: Carefully review and note the names of all variables in the dataset. Examples of these variables include:
Mileage (mpg)
Number of Cylinders (cyl)
Displacement (disp)
Horsepower (hp)
Research: Google to understand these variables.
Statistical Analysis: Select mpg variable, and perform the following statistical tests. Once you are done with these tests using mpg variable, repeat the same with hp
Mean
Median
First Quartile (Q1)
Second Quartile (Q2)
Third Quartile (Q3)
Fourth Quartile (Q4)
10th Percentile
70th Percentile
Skewness
Kurtosis
Document Your Results:
In RStudio: Before running each statistical test, provide a heading in the format shown at the bottom. “# Mean of mileage – Your name’s command”
In Microsoft Word: Once you've completed all tests, take a screenshot of your results in RStudio and paste it into a Microsoft Word document. Make sure that snapshots are very clear. You will need multiple snapshots. Also transfer these results to the…
Chapter 11 Solutions
Introductory Statistics (10th Edition)
Ch. 11.1 - What is meant by saying that a variable has a...Ch. 11.1 - How are different chi-square distributions...Ch. 11.1 - Two 2-curves have degrees of freedom 12 and 20,...Ch. 11.1 - The t-table has entries for areas of 0.10, 0.05,...Ch. 11.1 - Prob. 5ECh. 11.1 - Prob. 6ECh. 11.1 - In Exercises 11.511.2, use Table VII to find the...Ch. 11.1 - Prob. 8ECh. 11.1 - Prob. 9ECh. 11.1 - Prob. 10E
Ch. 11.1 - Prob. 11ECh. 11.1 - Prob. 12ECh. 11.1 - When you use chi-square procedures to make...Ch. 11.1 - Give two situations in which making an inference...Ch. 11.1 - Prob. 15ECh. 11.1 - In each of Exercises 11.1511.20, we have provided...Ch. 11.1 - In each of Exercises 11.1511.20, we have provided...Ch. 11.1 - Prob. 18ECh. 11.1 - In each of Exercises 11.1511.20, we have provided...Ch. 11.1 - Prob. 20ECh. 11.1 - Prob. 21ECh. 11.1 - Prob. 22ECh. 11.1 - Preliminary data analyses and other information...Ch. 11.1 - Preliminary data analyses and other information...Ch. 11.1 - Prob. 25ECh. 11.1 - Prob. 26ECh. 11.1 - In Exercises 11.2711.32, use Procedure 11.2 on...Ch. 11.1 - Prob. 28ECh. 11.1 - Prob. 29ECh. 11.1 - In Exercises 11.2711.32, use Procedure 11.2 on...Ch. 11.1 - Prob. 31ECh. 11.1 - Prob. 32ECh. 11.1 - Prob. 33ECh. 11.1 - Prob. 34ECh. 11.1 - Prob. 35ECh. 11.1 - In each of Exercises 11.3311.36, use the...Ch. 11.1 - Body Temperature. A study by researchers at the...Ch. 11.1 - Dexamethasone and IQ. In the paper Outcomes at...Ch. 11.1 - Forearm Length. In 1903, K. Pearson and A. Lee...Ch. 11.1 - Prob. 40ECh. 11.2 - How many numbers of degrees of freedom does an...Ch. 11.2 - What symbol is used to denote the F-value having...Ch. 11.2 - Prob. 44ECh. 11.2 - An F-curve has df = (12, 7). What is the number of...Ch. 11.2 - Prob. 46ECh. 11.2 - Prob. 47ECh. 11.2 - In Exercises 11.4711.54, use Table VIII and, if...Ch. 11.2 - Prob. 49ECh. 11.2 - Prob. 50ECh. 11.2 - Prob. 51ECh. 11.2 - In Exercises 11.4711.54, use Table VIII and, if...Ch. 11.2 - In Exercises 11.4711.54, use Table VIII and, if...Ch. 11.2 - Prob. 54ECh. 11.2 - In using F-procedures to make inferences for two...Ch. 11.2 - Give two situations in which comparing two...Ch. 11.2 - Prob. 57ECh. 11.2 - Prob. 58ECh. 11.2 - Prob. 59ECh. 11.2 - Prob. 60ECh. 11.2 - In each of Exercises 11.5711.62, we have provided...Ch. 11.2 - Prob. 62ECh. 11.2 - Prob. 63ECh. 11.2 - Preliminary data analyses and other information...Ch. 11.2 - Prob. 65ECh. 11.2 - Preliminary data analyses and other information...Ch. 11.2 - Prob. 67ECh. 11.2 - Preliminary data analyses and other information...Ch. 11.2 - Prob. 69ECh. 11.2 - Prob. 70ECh. 11.2 - Prob. 71ECh. 11.2 - Prob. 72ECh. 11.2 - Prob. 73ECh. 11.2 - Prob. 74ECh. 11.2 - The Etruscans. Anthropologists are still trying to...Ch. 11.2 - Prob. 76ECh. 11.2 - RBC Transfusions. In the article Reduction in Red...Ch. 11.2 - Prob. 79ECh. 11 - What distribution is used in this chapter to make...Ch. 11 - Fill in the blanks. a. A 2-curve is _____ skewed....Ch. 11 - When you use the one-standard-deviation 2-test or...Ch. 11 - Prob. 4RPCh. 11 - Prob. 5RPCh. 11 - Prob. 6RPCh. 11 - Prob. 7RPCh. 11 - Prob. 8RPCh. 11 - What distribution is used in this chapter to make...Ch. 11 - Fill in the blanks: a. An F-curve is ____ skewed....Ch. 11 - When you use the two-standard-deviations F-test....Ch. 11 - Prob. 12RPCh. 11 - Prob. 13RPCh. 11 - Prob. 14RPCh. 11 - Prob. 15RPCh. 11 - Prob. 16RPCh. 11 - Prob. 17RPCh. 11 - Prob. 18RPCh. 11 - Prob. 19RPCh. 11 - Prob. 20RPCh. 11 - Prob. 21RPCh. 11 - Prob. 22RPCh. 11 - Prob. 23RPCh. 11 - Microwave Popcorn. Two brands of microwave...Ch. 11 - Recall from Chapter 1 (see page 34) that the Focus...Ch. 11 - At the beginning of this chapter, we discussed...
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