Question

SOC364/L - Social Statistics @ CSUN w Godard Homework #5: Confidence intervals & Samples Sizes This assignment need not be typed but must be legible. (The instructor is the arbiter of legibility.) Be as complete as possible in your answers. On this and all assignments, put all answers in prose form (sentences and paragraphs); single-word or phrase answers are not sufficient. Be explicit and complete in explaining your answers. Show all work done, including any calculations, & explain all of the steps involved and all of the parts of each calculation. Hint for all problems: Draw a picture first!! I From the Agresti & Finlay problems for chapter 5 (pp. 133-141), do these 7 problems, in this order. 22, 20, 4, 40, 14, 67, and 68 II. Using the GSS84.SAV dataset in SPSS, find 95% and 99% confidence intervals for the mean age and for the proportion female in the sample (four confidence intervals, in total). Use SPSS to get the summary statistics only; calculate the confidence intervals by hand, and show all work. Be sure to include your calculations, interpretations (!), and conclusions.

Answer 1

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Please post the remaining questions in a new post.

Part II

1. State the null hypothesis H, and the alternative hypothesis H, that would be used for a hypothesis test related to each of the following statements. Clearly specify whether they are one or two-tailed tests: a. The mean age of students enrolled in evening classes at Piedmont Community College is greater than 26 years. b. The mean distance from a hotel room in Amsterdam to the nearest museum is less than 200 yards. c. The mean life of a carburetor is 10,000 miles. d. The mean weight of college football players is no more than 210 lbs. e. One in ten CSUN students has been arrested for public drunkenness

1.

a. one tail test(right)

HO: The mean age of students enrolled in evening classes at Piedmont community college is equal to 26 years.
H1 :The mean age of students enrolled in evening classes at Piedmont community college is greater to 26 years.

b. one tail test (left)
Ho. The mean distance from a hotel room in Amsterdam to the nearest museum is equal to 200 yards
H1. The mean distance from a hotel room in Amsterdam to the nearest museum is less than 200 yards

c. Two tail test
Ho: the mean life of a carburetor is 10,000 miles
H1: the mean life of a carburetor is not 10,000 miles

d. One tail test

H1: The mean weight of college football player is equal to 210 lbs
H0 : The mean weight of college football player is less than to 210 lbs

e. two tail test

H1:the proportion of the students arrested for public drunkness is 0.10
H0:the proportion of the students arrested for public drunkness is not equal to 0.10

2.

2. For a large-sample test of Ho: Mu = 0 against H: Mu is not equal to 0, the z statistic equals 1.07 a. Find the p-value, and interpret it. b. Suppose z = -2.51 rather that 1.07- Find the p-value and interpret it. C. Does the larger z score mean stronger or weaker evidence in re the null hypothesis? Explain.

Note :Excel is used to find the pvalue. The formulas are also shown.

a. Zstat = 1.07 pvalue = 0.14231 =1-NORM.S.DIST(1.07,TRUE) Hence we fail to reject null hypothesis, as the pvalue is greater than 0.05 1b. Zstat = -2.51 pvalue = 0.006037 ENORM.S.DIST(-2.51, TRUE) Hence pvalue is less than 0.01, hence reject the null hypothesis. c. As the zscore is larger, it give rise to a very small pvalue, hence giving strong evidence against the null hypothesis.