**Business Statistics**

__Please answer the following questions__

__Module 3 – Assignment__

**Q1: # 27 Social Media**: application problem on relationships of probability.

A marketing firm would like to test-market the name of a new energy drink targeted at 18- to 29-year-olds via social media. A study by the Pew Research Center found that 35% of U.S. adults (18 and older) do not use social media (*Pew Research Center* website, October 2015). The percentage of U.S. young adults age 30 and older is 78%. Suppose that the percentage of the U.S. adult population that is either age 18–29 or uses social media is 67.2%.

1. What is the probability that a randomly selected U.S. adult uses social media?

2. What is the probability that a randomly selected U.S. adult is aged 18–29?

3. What is the probability that a randomly selected U.S. adult is 18–29 and a user of social media?

**Your Answer:**

**——-**

**Q2: # 37** **Giving Up Electronics**: application problem on conditional probability.

A 2018 Pew Research Center survey found that more Americans believe they could give up their televisions than could give up their cell phones (Pew Research website). Assume that the following table represents the joint probabilities of Americans who could give up their television or cell phone.

1. What is the probability that a person could give up her cell phone?

2. What is the probability that a person who could give up her cell phone could also give up television?

3. What is the probability that a person who could not give up her cell phone could give up television?

4. Is the probability a person could give up television higher if the person could not give up a cell phone or if the person could give up a cell phone?

**BUSI 3301 – Business Statistics**

__Module 5 Assignment__

**Name: ——————- JCC ID: ————**

**Q1: #21. Telemedicine**: application problem on the confidence interval of population mean.

Health insurers are beginning to offer telemedicine services online that replace the common office visit. WellPoint provides a video service that allows subscribers to connect with a physician online and receive prescribed treatments (*Bloomberg Businessweek*). WellPoint claims that users of its Live Health Online service saved a significant amount of money on a typical visit. The data shown below ($), for a sample of 20 online doctor visits, are consistent with the savings per visit reported by WellPoint.

92 |
93 |
83 |
93 |
40 |

105 |
78 |
49 |
82 |
96 |

56 |
53 |
48 |
40 |
73 |

76 |
34 |
74 |
55 |
100 |

Assuming the population is roughly symmetric, construct a 95% confidence interval for the mean savings for a tele visit to the doctor as opposed to an office visit.

**Your Answer:**

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**Q2: #35. Health-Care Survey: **application problem on the confidence interval of population proportion.

In the spring of 2017, the Consumer Reports National Research Center conducted a survey of 1007 adults to learn about their major health-care concerns. The survey results showed that 574 of the respondent’s lack confidence they will be able to afford health insurance in the future.

- What is the point estimate of the population proportion of adults who lack confidence they will be able to afford health insurance in the future?
- At 90% confidence, what is the margin of error?
- Develop a 90% confidence interval for the population proportion of adults who lack confidence they will be able to afford health insurance in the future.
- Develop a 95% confidence interval for this population proportion.

**Your Answer:**

—————–

**Assignment 6**

**Q1**: The random variable *x* is known to be uniformly distributed between 10 and 20.

1. Compute *P*(12 ≤ *x* ≤ 18).

2. Compute *E*(*x*).

3. Compute *Var*(*x*).

Q1: ** Process Improvement.** Because of high production-changeover time and costs, a director of manufacturing must convince management that a proposed manufacturing method reduces costs before the new method can be implemented. The current production method operates with a mean cost of $220 per hour. A research study will measure the cost of the new method over a sample production period.

1. **Develop the null and alternative hypotheses most appropriate for this study.**

2. **Comment on the conclusion when H_{0} cannot be rejected.**

3. **Comment on the conclusion when H_{0} can be rejected.**