Homework answers / question archive / 1)A random sample of 20 items is selected from a population

1)A random sample of 20 items is selected from a population

Statistics

Share With

1)A random sample of 20 items is selected from a population. When computing a confidence interval for the population mean, what number of degrees of freedom should be used to determine the appropriate t-value?

2. The manager of Paul's fruit and vegetable store is considering the purchase of a new seedless watermelon from a wholesale distributor. Since this seedless watermelon costs $4, will sell for $7, and is highly perishable, he only expects to sell between six and nine of them. What is the opportunity loss for purchasing nine watermelons when the demand is for seven watermelons?
3. Checklists with several items to be considered by respondents may be subject to _____.
4. Which of the following goals should a good survey instrument accomplish?
5. Which of the following is most appropriately displayed with a frequency table?
6. Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers has maintained careful records regarding the time to prepare a return. The mean time to prepare a return is 90 minutes and the standard deviation of this distribution is 14 minutes. Suppose 100 returns from this year are selected and analyzed regarding the preparation time. What assumption do you need to make about the shape of the population distribution of all possible tax preparation times to make inferences about the mean time to complete a tax form?
7. A large department store examined a sample of the 18 credit card sales and recorded the amounts charged for each of three types of credit cards: MasterCard, Visa, and Discover. Six MasterCard sales, seven Visa, and five Discover sales were recorded. The store used an ANOVA to test if the mean sales for each credit card were equal. What are the degrees of freedom for the F statistic?
8. Consider a regression analysis, where the correlation coefficient is 0.18. Then, the coefficient of determination is
9. Which of the following is a characteristic of the F distribution?
10. The question, "Should products be withdrawn if even one death is associated with its prescribed use, even if no fault for the tampered product accrues to the manufacturer?" is an example of a(n) _____. 
11. What is the interpretation of a 96% confidence level?
12. A firm offers routine physical examinations as part of a health service program for its employees. The exams showed that 8% of the employees needed corrective shoes, 15% needed major dental work, and 3% needed both corrective shoes and major dental work. What is the probability that an employee selected at random will need either corrective shoes or major dental work?
13. When data is collected using a qualitative, nominal variable, what is true about a frequency distribution that summarizes the data?
14. A ranking scale is a scale that _____.
15. For any chi-square goodness-of-fit test, the number of degrees of freedom is found by ______. 
16. A sales manager for an advertising agency believes that there is a relationship between the number of contacts that a salesperson makes and the amount of sales dollars earned. What is the dependent variable?
17. For a chi-square test involving a contingency table, suppose the null hypothesis is rejected. We conclude that the two variables are __________. 
18. A random sample of size 15 is selected from a normal population. The population standard deviation is unknown. Assume the null hypothesis indicates a two-tailed test and the researcher decided to use the 0.10 significance level. For what values of t will the null hypothesis not be rejected?
19. If an ANOVA test is conducted and the null hypothesis is rejected, what does this indicate?
20. Sam's Club installed self-checkout stations that can track not only member's purchases but also packaging problems, as the system uses universal product codes to match the item the shopper has in their cart with its price and inventory level in the store, generating a spreadsheet style report for the researcher. If you consider the scanner as the tool for collecting data for Sam's researchers, they are doing data entry by ____
21. In a multiple rating list scale, ____. 
22. An experimental study is one that _____. 
23. BankChoice is concerned about stagnating profits and asks, "How can profitability be improved?" This is an example of a(n) _____.
24. As the size of the sample increases, what happens to the shape of the distribution of sample means?
25. The monthly salaries of a sample of 100 employees were rounded to the nearest $10. They ranged from a low of $1,040 to a high of $1,720. If we want to condense the data into seven classes, what is the most convenient class interval?
26. The weekly incomes of a large group of executives are normally distributed with a mean of $2,000 and a standard deviation of $100. What is the z-score for an income of $2,100?
27. A machine is set to fill the small-size packages of M&M candies with 56 candies per bag. A sample revealed three bags of 56, two bags of 57, one bag of 55, and two bags of 58. To test the hypothesis that the mean candies per bag is 56, how many degrees of freedom are there?
28. In multiple regression analysis, when the independent variables are highly correlated, this situation is called __________________. 

Ans: Autocorrelation

29. A linear trend equation is used to represent time series values when the data are changing by equal what?
30. Kroger, a grocery store chain, wants to identify the ideal store layout for increasing store sales. Because it primarily uses two store designs, one a grid layout with vertical aisles divided by a center aisle and another using a traditional straight-aisle pattern, Kroger will match pairs of stores that have different designs but similar shopper demographics and location. Sales from each pair will then be compared to determine if store design is related to sales. Which type of study is this an example of?