Nov 29, 2016

- Provide an appropriate response.
**1.**Define random sample. Explain why this is important in design of experiments.*Possible answer*

- Determine whether the given value is a statistic or a parameter.
**2.**A sample of 120 employees of a company is selected, and the average age is found to be 37 years.- Parameter
- Statistic

- Identify the number as either continuous or discrete.
**3.**The number of freshmen entering college in a certain year is 621.- Continuous
- Discrete

- Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate.
**4.**Survey responses of “good, better, best”.- Nominal
- Interval
- Ordinal
- Ratio

**5.**Salaries of college professors.- Ratio
- Interval
- Ordinal
- Nominal

- Identify the sample and population. Also, determine whether the sample is likely to be representative of the population.
**6.**An employee at the local ice cream parlor asks three customers if they like chocolate ice cream.- Sample: the 3 selected customers
- Population: all customers
- Representative
- Sample: all customers
- Population: the 3 selected customers
- Not representative

- Use critical thinking to develop an alternative conclusion.
**7.**In a study of headache patients, every one of the study subjects with a headache was found to be improved after taking a week off of work. Conclusion: taking time off work cure headaches.*Possible answer*

- Use critical thinking to address the key issue.
**8.**An airline company advertises that 100% of their flights are on time after checking 5 randomly selected flights and finding that these 5 were on time.*Possible answer***9.**“38% of adults in the United States regularly visit a doctor”. This conclusion was reached by a college student after she had questioned 520 randomly selected members of her college. What is wrong with her survey?*Possible answer*

- Perform the requested conversions. Round decimals to the nearest thousandth and percent to the nearest tenth of a percent, if necessary.
**10.**Convert 0.4 to an equivalent fraction and percentage.^{3}/_{10}, 4%^{3}/_{10}, 40%^{2}/_{5}, 40%^{2}/_{5}, 4%

**11.**Convert 90% to an equivalent fraction and decimal.^{9}/_{10}, 9^{4}/_{5}, 0.9^{9}/_{10}, 0.9^{4}/_{5,}9

- Solve the problem.
**12.**On a test, if 125 questions are answered and 68% of them are correct, what is the number of correct answers?- 90
- 85
- 62
- 54

- Is the description an observational study or an experiment?
**13.**A stock analyst compares the relationship between stock prices and earnings per share to help him select a stock for investment.- Observational study
- Experiment

**14.**A TV show’s executives raised the fee for commercials following a report that the show received a “No. 1” rating in a survey of viewers.- Experiment
- Observational study

- Identify the type of observational study.
**15.**A town obtains current employment data by polling 10,000 of its citizens this month.- Prospective
- None of these
- Cross-sectional
- Retrospective

- Identify which of these types of sampling is used: random, stratified, systematic, cluster, convenience.
**16.**49, 34, and 48 students are selected from the Sophomore, Junior, and Senior classes with 496, 348, and 481 students respectively.- Systematic
- Stratified
- Cluster
- Convenience

**17.**A sample consists of every 49^{th}student from a group of 496 students.- Convenience
- Systematic
- Cluster
- Stratified

**18.**The name of each contestant is written on a separate card, the cards are placed in a bag, and three names are picked from the bag.- Systematic
- Convenience
- Random
- Cluster
- Stratified

- Provide an appropriate response.
**19.**Explain what is meant by the term “confounding” and give an example of an experiment in which confounding is likely to be a problem.*Possible answer***20.**A researcher wants to obtain a sample of 100 school teachers from the 800 school teachers in a school district. Describe procedures for obtaining a sample of each type: random, systematic, convenience, stratified, cluster.*Possible answer*

**Directions:**

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