Week 7: Week Seven – Class Discussion
Interpret probability models for random variables.
It is well-documented that parents actively smoking during pregnancy is associated with lower-birth-weight babies. Researchers Fernando D. Martinez and associates wanted to determine if there is a relationship between paternal smoking habits and birth weight. The researchers administered a questionnaire to each parent of newborn infants. One question asked whether the individual smoked regularly. Because the survey was administered within 15 days of birth, it was assumed that any regular smokers were also regular smokers during pregnancy. Birth weights for the babies (in grams) of nonsmoking mothers were obtained and divided into two groups, nonsmoking fathers and smoking fathers. The given data below represents the data collected by the researchers. The researchers concluded that the birth weight of babies whose father smoked was less than the birth weight of babies whose father did not smoke.
Answer the following questions for your main post:
Nonsmokers
4194
3522
3454
3062
3771
3783
3544
3746
4019
4248
3719
3668
3128
3290
3423
3471
4354
3544
3994
2976
4067
3732
3823
3302
3436
3976
3263
Smokers
3998
3455
3066
3150
2986
2918
4216
3502
3457
2860
3282
2746
3686
2851
3145
3807
3548
4104
3963
3892
2768
3769
3509
3629
4131
3129
4263
Is this an observational study or a designed experiment? Why?
What is the explanatory variable? What is the response variable?
Can you think of any lurking variables that may affect the results of the study?
Go to.xuru.org/st/DS.asp”>http://www.xuru.org/st/DS.asp and find the summary statistics for both non-smokers and smokers (mean, median, standard deviation, quartiles.) Compute each group separately. Report your findings. Note: Copy the data from the tables and place in the large box on the page and separate each item by a comma.
Why is the sample standard different from the population standard deviation? Which should you use in this study, and why?
Using your results, write up a practical summary of what you are seeing in this data. Do you agree with the researchers conclusions based on your analysis?
