1. The speed of an airplane in miles per hour is a ___________________ variable.
2. A football team's rank is a ___________________________variable.
3. The __________________ for a set of data is found by adding all the data values and dividing by the number of items.
4. The range or the ______________________________ can be used for measuring the variability of ordinal variables.
5. The mode is the only measure of central tendency for _____________________ data.
6. A ____________________ variable affects a ____________________.
7. The ____________________measures the variability of the dependent variable based on the variability of the independent variable.
8. A _______________________________is a graphical representation for analyzing the relationship between categorical variables.
9. A _____________________________ is a graphical representation for analyzing the relationship between numerical variables.
10. When we are looking at the association between an independent variable and a dependent variable we are doing a _________________.
11. The measure of association for numerical variables is ______________________________.
12. The two measures of association most commonly used for ordinal variables are _____________________and ______________________.
13. For the Chi-squared Test for Independence the ___________________ states that there is an association between the two variables.
14. The error that may occur by rejecting the null hypothesis is called ___________________________.
15. The error that may occur by accepting the null hypothesis is called _______________________________.
16. The likelihood that a test statistic of a particular magnitude computed from a sample is indicated by the ______________________.
17. A hypothetical distribution of the characteristics of all possible samples of a certain size drawn from a population is the ___________________________________.
18. The standard deviation of the sampling distribution of the sample means is the _______________________________.
19. A theory about the sampling distribution which tells us that the larger the size of the sample from a population is the more likely it is that the mean of a single sample will be close to the mean of the population is called the ____________________________________.
20. ________________________________ are numbers that help us assess the likelihood that patterns we observe in randomly drawn samples will be found in the populations from which those samples were drawn.
Part II: Short Answers
1) A random sample of 81 automobile tires has a mean tread life of 36,000 miles. It is known that the standard deviation of the tread life of the tires is 4500 miles.
a. A 95% confidence interval for the population mean is:
b. If the sample mean of 36,000 had been from a random sample of size 50, the 95% confidence interval would have been (pick one of the below statements)
i. The same
ii. A wider interval
iii. A narrower interval
2) Consider the following two-tailed test:
Assume that and that a sample of size 100 resulted in a sample mean of .
a) What is the value of the test statistic?
b) At the 0.05 level of significance, what conclusion should be reached?
3) An accountant believes that the company's cash flow problems are a direct result of the slow collection of accounts receivable. The accountant claims that at least 70% of the current accounts receivable are over 2 months old. A sample of 120 accounts receivable yielded 78 over 2 months old.
a) What is the value of the test statistic?
a) At the 0.05 level of significance, is the accountant correct?
4) Use the following for questions. A testing company is checking to see if there is any significant difference in the coverage of two different brands of paint for a hardware store chain. The results are summarized below.
Amazon Paints Cover up Paint
Mean coverage (in square feet) 305 295
Standard Deviation 20 25
Sample size 31 41
a) A point estimate of the difference between the population mean is
b) A estimate of the standard error of the difference between the sample means is
c) If a two-tailed test is used with a 0.05 level of significance, what conclusion would the testing company make if they thought that there was no difference in the mean coverage of the two paints?
5) Analyzing SAT Scores: The College of Newport randomly selects female applicants for admission and records their scores on the math portion of the SAT. Here are the results:
490, 570, 630, 440, 460, 720, 410, 780
a. Find the mean of this sample.
b. Find the standard deviation.
c. Using a 0.05 significance level to test the claim that this sample comes from a population with a mean equal to 496, which is the reported mean of SAT math scores for all women.
Part 3: Answer the following questions using SPSS and the GSS data (GSS 2002 subset C - Attached).
1. Researchers say that there is a relationship between how fundamental one is and their views on whether birth control pills should be given to teenagers. To test this GSS survey asked respondents how fundamental they are in their views and whether giving birth control pills are okay to teenagers. Write a few sentences analyzing the relationship between pillok and fund using the appropriate measure of association.
2. Researchers believe that people who go to church tend to be happier in general. Test to see if there is an association between rcattend and happy using the Chi-Squared Test of Independence.
3. In the past, the average household had 2.5 children. Use the one-sample t-test to determine if that is true using the variable rchilds.
The solution provides step by step method for analysis of GSS data in SPSS . Formula for the calculation and Interpretations of the results are also included.