Quiz 5

Quiz 5

The End is Near!

Multiple Choice

1. Identify the type of sampling used in the following the scenarios:

a. The program coordinator for ACC mathematics collects the grade averages of 7 randomly chosen students from each of the 23 math courses available.

• Simple Random Sampling

• Systematic Sampling

• Convenience Sampling

• Stratified Sampling

Multiple Choice

1. Identify the type of sampling used in the following the scenarios:

b. You decide to ask your co-workers whether they think pineapple belongs on pizza.

• Simple Random Sampling

• Systematic Sampling

• Convenience Sampling

• Stratified Sampling

Multiple Choice

1. Identify the type of sampling used in the following the scenarios:

c. It’s 3 a.m. and you decide to see who is awake and what their current mood is (for scientific purposes of course). It’d be totally silly to have the entire neighborhood mad at you, so you decide to knock on every house whose address is divisible by 5.

• Simple Random Sampling

• Systematic Sampling

• Convenience Sampling

• Stratified Sampling

Multiple Choice

1. Identify the type of sampling used in the following the scenarios:

d. You set up a robocall program that surveys people over their frustration with automated systems. The program selects numbers at random from a database to call.

• Simple Random Sampling

• Systematic Sampling

• Convenience Sampling

• Stratified Sampling

Open Ended

2. Explain the difference between:

a. An observational study and an experiment.

observational study vs. experiment.

In an experiment, the experimenter takes an active role in the behavior of the participant. Control and treatment groups are assigned by actions from the experimenter.

In an observational study, the data is collected from passively observing the outcome of events.

In some instances, studies may coincidentally line themselves up like an experiment with control and treatment groups. These are called retrospective studies.

Open Ended

2. Explain the difference between:

b. The treatment and control group.

treatment vs control group

Treatment group receives the active treatment.

Control group does not receive the treatment. They may receive an inert placebo to account for the placebo effect.

Open Ended

2. Explain the difference between:

c. A single-blind and double-blind experiment.

single-blind and double-blind

In a single-blind study, the participant is not aware whether they are receiving the treatment or placebo.

In a double-blind study, neither the participant nor the experimenter are aware whether they are receiving the treatment or placebo.

Fill in the Blank

3. Despite all the recent scandals, a poll indicates that 62% of the surveyed voters intend to vote for the incumbent Mayor McHorrible . He needs 45% of the vote to win without a run-off. The margin of error on the poll is 12%. Will McHorrible re-win his mayoral seat?

Find the confidence interval.

If we consider the margin of error, the poll indicates that LOWEST McHorrible might get is _ of the vote.

Fill in the Blank

3. Despite all the recent scandals, a poll indicates that 62% of the surveyed voters intend to vote for the incumbent Mayor McHorrible . He needs 45% of the vote to win without a run-off. The margin of error on the poll is 12%. Will McHorrible re-win his mayoral seat?

Find the confidence interval.

If we consider the margin of error, the poll indicates that HIGHEST McHorrible might get is _ of the vote.

Multiple Choice

3. Despite all the recent scandals, a poll indicates that 62% of the surveyed voters intend to vote for the incumbent Mayor McHorrible . He needs 45% of the vote to win without a run-off. The margin of error on the poll is 12%. Will McHorrible re-win his mayoral seat?

Be sure to explain.

• McHorrible should expect to win based on the poll.

• McHorrible should NOT expect to win based on the poll.

Open Ended

4. Should You Believe This Study? Based solely on the information given, do you have reason to question the results or the methods used in the following hypothetical studies? Explain your reasoning.

a. A study by Sweetums show that their Sugar Splash Soda reduces the risk of diabetes by 13%.

a. A study by Sweetums show that their Sugar Splash Soda reduces the risk of diabetes by 13%.

2. Consider the Source.

The source of the study is a company that benefits from it's outcome.

Open Ended

4. Should You Believe This Study? Based solely on the information given, do you have reason to question the results or the methods used in the following hypothetical studies? Explain your reasoning.

b. A survey conducted among ACC students found that 13% found their math professor to be “too nice”, 24% found them to be “too mean”, 5% found them to be “just right” and 58% had no response.

b. A survey conducted among ACC students found that 13% found their math professor to be “too nice”, 24% found them to be “too mean”, 5% found them to be “just right” and 58% had no response.

4. Look for Problems in Defining or Measuring the Variables of Interest. 

The variables "too nice", "too mean", and "just right" are subjective terms and not well defined.

Open Ended

4. Should You Believe This Study? Based solely on the information given, do you have reason to question the results or the methods used in the following hypothetical studies? Explain your reasoning.

c. The Home Shopping Network conducted a survey to find out what was the most popular genre of music for Americans. They urged their watchers to mail a letter listing their top 3 favorite genres of music.

c. The Home Shopping Network conducted a survey to find out what was the most popular genre of music for Americans. They urged their watchers to mail a letter listing their top 3 favorite genres of music.

3. Look for Bias in the Sample. (selection/participation)

The survey is hoping to gather information about the population of all Americans.

The survey limits it's sample to people that watch Home Shopping Network which is selection bias.

The survey also requires people to mail in their responses, which is an extra barrier that will create participation bias.

Open Ended

4. Should You Believe This Study? Based solely on the information given, do you have reason to question the results or the methods used in the following hypothetical studies? Explain your reasoning.

d. A survey conducted contains the question, “Do you support the abolition of basic human rights?”

d. A survey conducted contains the question, “Do you support the abolition of basic human rights?”

6. Consider the Setting and Wording in Surveys. 

The word "support" is a leading term and "abolition" is a typically agreeable term as well as "human rights", but when strewn together create an absurd question that I hope everyone disagrees with. Hopefully we all favor basic human rights.

Open Ended

4. Should You Believe This Study? Based solely on the information given, do you have reason to question the results or the methods used in the following hypothetical studies? Explain your reasoning.

e. A study conducted measured the concentration of limestone in the tap water for Kyle, TX and Houston, TX. It found that there were higher concentrations of limestone in the Kyle tap water. The study compared this finding to medical records that indicate a higher prevalence of respiratory illness in Houston to conclude that limestone may prevent respiratory illness.

e. A study conducted measured the concentration of limestone in the tap water for Kyle, TX and Houston, TX. It found that there were higher concentrations of limestone in the Kyle tap water. The study compared this finding to medical records that indicate a higher prevalence of respiratory illness in Houston to conclude that limestone may prevent respiratory illness.

5. Beware of Confounding Variables. 

You may have to pull in what you know about Kyle vs Houston, but this is really hinting at the fact that there is a third underlying variable that probably plays a much bigger role and that is "air quality". Kyle is a smaller town with less air pollutants that the large industrial city of Houston.

Multiple Choice

5. The following numbers represents scores on an exam from a class of 33 students:

65 92 99 74 57 56 75 80 69 74 66 73

56 72 85 95 60 82 50 72 75 71 67 53

83 58 71 56 56 53 98 83 78

a. Is this a qualitative or quantitative variable?

• Qualitative

• Quantitative

5. The following numbers represents scores on an exam from a class of 33 students:

65 92 99 74 57 56 75 80 69 74 66 73

56 72 85 95 60 82 50 72 75 71 67 53

83 58 71 56 56 53 98 83 78

b. Complete the following table.

5. The following numbers represents scores on an exam from a class of 33 students:

65 92 99 74 57 56 75 80 69 74 66 73

56 72 85 95 60 82 50 72 75 71 67 53

83 58 71 56 56 53 98 83 78

c. Create a histogram for the score and frequency.

5. The following numbers represents scores on an exam from a class of 33 students:

65 92 99 74 57 56 75 80 69 74 66 73

56 72 85 95 60 82 50 72 75 71 67 53

83 58 71 56 56 53 98 83 78

c. Create a histogram for the score and frequency.

Multiple Choice

6. The following letter grades represent scores on an exam from a class of 18 students:

C, A, D, C, F, A,

C, C, B, C, C, B,

B, C, A, B, D, F

a. Is this a qualitative or quantitative variable?

• Qualitative

• Quantitative

6. The following letter grades represent scores on an exam from a class of 18 students:

C, A, D, C, F, A,

C, C, B, C, C, B,

B, C, A, B, D, F

b. Complete the following table.

6. The following letter grades represent scores on an exam from a class of 18 students:

C, A, D, C, F, A,

C, C, B, C, C, B,

B, C, A, B, D, F

c. Complete a Pie Chart for the grade distribution of the above class.

Making a pie chart

Use the relative frequency to portion the circle.
Since the denominator is 18, we can figure out that  $\frac{1}{18}\times360\degree=20\degree$  

Therefore,

  $\frac{3}{18}\ is\ 60\degree$  

 $\frac{4}{18}\ is\ 80\degree\$