Researchers are studying the relationship between honesty, age, and self-control conducted an experiment on 160 children between the ages of 5 and 15. The researchers asked each child to toss a fair coin in private and to record the outcome (heads or tails) on a paper sheet, and said they would only reward children who report heads. Half the students were explicitly told not to cheat and the others were not given any explicit instructions. Differences were observed in the cheating rates in the instruction and no instruction groups, as well as some differences across children's characteristics within each group.

a) Identify the population of interest in the study.

b) Identify the sample for this study.

c) Can the results of the study be generalized to the population? Should the findings of the study be used to establish causal relationships.

• All children between the ages of 5 and 15
• 160 children between the ages of 5 and 15
• If the sample is randomly selected and representative of the entire population, then the results can be generalized to the target population. Furthermore, since this study is experimental, the findings can be used to infer causal relationships.

A restaurant owner is interested in the proportion of his customers who order dessert. He looks at 65 randomly selected receipts. Match the vocabulary word with its corresponding example.

• The answer: Yes or No to whether a customer ordered dessert
• The proportion of the 65 randomly selected customers who ordered dessert
• All customers who come to the restaurant
• The proportion of all customers who order dessert
• The list of the 65 Yes or No answers for whether each customer ordered dessert.
• The 65 restaurant patrons whose receipts were observed by the owner

• variable
• statistics
• populations
• parameter
• data
• sample

A state university is interested in where its students come from. They survey 300 of its students to find out if they are in-state, out-of-state, or foreign students. Match the vocabulary word with its corresponding example.

• All students at the university
• The proportion of the 300 surveyed students who are in-state students
• The list of the 300 answers to the survey question
• The answer in-state out-of-state or foreign
• The 300 students who were surveyed
• The proportion of all students from this university who are in-state students

• population
• Statistic
• Data
• Variable
• Sample
• Parameter

A web administrator is interested in the average number of visitors per day that her website receives. Match the vocabulary word with its corresponding example.

• The 42 randomly selected days that the administrator tracked
• The average number of visitors per day for the 42 days that the administrator tracked
• All the days that the website has been in existence
• The list of visitor counts for the 42 days that were tracked
• The average number of visitors per day that have come to the website since it was created

1. Variable
2. Sample
3. Statistic
4. Population
5. Data
6. Parameter

Political pollsters may be interested in the proportion of people that will vote for a particular cause. Match the vocabulary word with its corresponding example.

• All the voters in the district
• The proportion of the 750 survey participants who will vote for the cause
• The answer Yes or No to the survey question
• The proportion of all voters from the district who will vote for the cause
• The list of 750 Yes or No answers to the survey question
• The 750 voters who participated in the survey

1. Population
2. Statistic
3. Variable
4. Parameter
5. Data
6. Sample

Number of tickets sold to a concert

Quantitative - Discrete

In a study, the data you collect is student id numbers.

What type of data is this?

Qualitative (Categorical)

Identify the type of data that would be used to describe a response.

Students' GPAs

Quantitative - Continuous

Identify the type of data that would be used to describe a response.

Number of Students Enrolled at Skyline College

Quantitative - Discrete

Is this value from a discrete or continuous data set.

The number of children a person has

Quantitative - Discrete

In a study, the data you collect is number of traffic tickets.

This data is:

Quantitative - Discrete

Identify the type of data that would be used to describe a response.

Number of pets that are owned

Quantitative - Discrete

In a study, the sample is chosen by choosing every 3rd person on a row

What is the sampling method?

Systematic

A researcher wants to survey 2000 Americans for an obesity study. Match the strategies to their corresponding sampling techniques.

• The researcher picks 20 different small groups:a church group a Democrat club a student club etc. each containing 100 people. Then the researcher makes sure that everyone from each group answers the survey question.
• The researcher posts the survey on the Internet the survey question and waits until 2000 people have responded.
• The researcher gets the complete list from the Census Bureau and uses a computer to randomly select 2000 people.
• The researcher gets the complete list from the Census Bureau and surveys every 1500th person on the list.
• The researcher makes sure that the proportion of respondents from each state matches the proportion of each state's population to the US population.

• Cluster Sampling
• Convenience Sampling
• Simple Random Sampling
• Systematic Sampling
• Stratified Sampling

A smart phone manufacturer wants to determine the average battery time that its new smart phone will get. The manufacturer will test 100 smart phones. Match the strategies to their corresponding sampling techniques.

• The manufacturer uses a computer to randomly select 150 smart phone serial numbers and tests all 150 phones with these serial numbers.
• The manufacturer tests every 1000th smart phone that comes off the assembly line.
• The manufacturer asks 100 of her friends who have the phone if she can borrow their phones to test.
• The manufacturer tests 20 smart phones from each of its five equally sized distributors.
• The manufacturer finds three small communities that have dry moderate and humid climates and every smart phone from each of these three communities is tested.

• Simple Random Sampling
• Systematic Sampling
• Convenience Sampling
• Stratified Sampling
• Cluster sampling

• surveying every 3rd driver coming through a tollbooth
• divide the population by age such that there are an equal number of people from each age group and select 5 people from each age group
• asking your 20 closest friends
• selecting five classroom numbers at random then surveying all the students in each of these five rooms
• number every name on a list and use a random number generator to select 50 random numbers (students)

• systematic
• stratified
• convenience
• cluster
• simple random

As part of a statistics project, Charlie would like to collect data on household size in his city. To do so, he asks each person in his statistics class for the size of their household and reports the results of a simple random sample. However, this is not a simple random sample. Why?

• Charlie did not use any randomization; he took a convenience sample.

In a study, the data you collect is Weight in pounds.

What is the level of measurement?

ratio

In a study, the data you collect is Gender.

What is the level of measurement?

Nominal

300 female Osprey hatch-lings were tracked until they died or succeeded in laying their own eggs. Based on the data, the researchers concluded that somewhere between 12% and 18% of all female Osprey hatch-lings in the US succeed in growing up to lay their own eggs.

Inferential Statistics

Determine if the following is an example of descriptive or inferential statistics.

A hospital administrator wants to see if fewer mistakes are made if nurses are forced to take frequent breaks. After observing a sample of 300 nurses who were not forced to take frequent breaks and 400 who were forced to take frequent breaks, it was clear from the data that implementing a policy to force nurses to take frequent breaks will decrease the average number of mistakes.

Inferential Statistics

85 randomly selected fifty-year-old Americans were asked how much money they had saved for their retirement. The average for these respondents was $25,000, the minimum was $0 and the maximum was $1,200,000.

descriptive statistics

Determine whether the following is an example of a sampling error or a non sampling error.

A researcher studied brother-sister pairs to see if there is a difference in IQ scores. Although the researcher made no mistakes in collecting the data, the findings showed that there was a difference when in reality there is no difference in IQ based on gender.

sampling error

Determine whether the following is an example of a sampling error or a non sampling error.

A sociologist surveyed 300 people about their level of anxiety on a scale of 1 to 100. Unfortunately, the person inputting the data into the computer accidentally transposed six of the numbers causing the statistics to have errors.

non sampling error

12% of all people are left handed. A researcher randomly selected 200 people and found that 16% of them were left handed. No mistakes were made in the data collection or data recording. The 4% difference is due to ...

sampling error

1. The people, animals or things on whom experiments are performed
2. a study in which data is collected without anything being done to the subjects
3. a study in which data from the past is examined
4. experimental conditions imposed on the subjects
5. a study in which a treatment is applied and responses are observed

• experimental units
• observational study
• retrospective study
• treatment
• experiment