Part I: Conceptual Questions, Ch. 1

**A. **You are paid to investigate the average amount that
households in the Greater Youngstown Area spend on grocery in a given quarter of
the year.

1. What is the variable of interest for this study?

2. What is the target population for this study?

3. What is the statistical entity for this study?

4. What is the parameter of interest for this study?

5. How would you make inference about that
parameter? Please be specific by listing the relevant statistic and the
estimator.

6. Why would you use a random sample for this study?
Please be specific.

7. Will the sample data that you collect be quantitative or qualitative? why?

8. Will the sample data that you collect be time-series or cross-sectional?
Why?

**B.** Do problem # 15, p. 26

Do parts a, b, c, d, only in addition to the following questions:

e. From the histogram in part 'd' describe the type of skewness in the distribution of the dataset.

f. Are there any outliers in the data on gross profit margin? Please show your solutions.

Hint: Compute the standardized value for the smallest and the largest values in the data.

B.

part 'c': What is the probability that both the commission and the council will refuse an application for zoning changes?

1. Complete the contingency table below for use in computing empirical probabilities.

Gender of Respondent | Response to Question | ||

?? ?? |
?? | ?? | Totals |

?? | ?? | ?? | |

?? | ?? | ?? | |

Totals | ?? | ?? | ?? |

**2a**. How many joint events are involved in this problem? List them.

**2b**. How many marginal events are involved in this problem? List them.**
3**. What is the probability that a respondent chosen at random

4.

Number of Service Calls per Day (X) | Number of Days (fj) |

0 | 8 |

1 | 10 |

2 | 22 |

3 | 9 |

4 | 1 |

Total | 50 |

1. What is the probability distribution of X?

2. Is this an example of a discrete or continuous probability distribution?
Explain.

3. Is this a valid probability distribution? Explain.

4. What is the most likely number of calls that the agency might receive in a
given day?

5. How many calls should the agency expect to receive in a given day?

**B.** Nine percent of undergraduate students carry credit card balances
greater than $7000 (Reader's Digest, July 2002). Suppose we randomly select 10
students from YSU and interview them about credit card usage.

1. Why is the selection of the 10 students a binomial experiment? Please be
specific.

2. What is the probability that two of the students will have a credit card
balance greater than $7000?

3. What is the probability that at least three students will have a credit card
balance greater than $7000?

4. Consider the outcomes in parts 'b' and 'c', which one is more likely and why?

5. Assuming the total enrollment this semester is 15,000, how many students
would you expect to carry credit card balances greater than $7000?

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**Copyright© 1996, Ebenge Usip, all rights reserved.
Last revised:
Tuesday, August 29, 2017.**