Population Random Convenience Sample and Bias

The set of ALL observations made on all objects under study for a given characteristic or variable.

• Sample

• Population

• Survey

• Parameter

A set of observations that constitute PART of the population.

• Statistic

• Census

• Population

• Sample

At a middle school, the 7th graders will conduct a survey for where to go on a field trip. Which method will result in the least biased decision?

• to randomly ask 8th grade students who went on a field trip last year

• to randomly choose some 7th grade students to select a location

• to ask all 7th grade teachers and administrators for a location

• to ask the student council to choose a location

Identify the type of sampling used:

Marianne wanted to know students' opinion on the new schedule at school. She survey's the first 30 students who come into her class.

• Convenience Sampling

• Systematic Random Sampling

• Simple Random Sampling

• Volunteer response

In order to estimate the proportion of students that text while driving, a school administrator selects a simple random sample of students from a list of all students at the school who have parking permits. The students are called to the office, one at a time. The administrator asks each student, “Do you text while driving, even though you are not supposed to?” Based on the survey, the administrator estimates that only 2% of students with parking passes text while driving. What potential bias is present in the design of this survey and what is the likely direction of the bias?

• The sample proportion is likely an underestimate of the population proportion due to response bias.

• The sample proportion is likely an underestimate of the population proportion due to undercoverage.

• The sample proportion is likely an underestimate of the population proportion due to nonresponse.

• The sample proportion is likely an overestimate of the population proportion due to response bias.

• The sample proportion is likely an overestimate of the population proportion due to undercoverage.

Tanya wants to know the percent of people likely to attend the upcoming musical at school. She asks each person in the musical how many people they know who are coming to make a prediction. Why is this sample biased?

• Drama students are more likely to lie.

• Musicals are better attended than plays.

• The drama teacher was not asked.

• The sample is not random and not representative of the entire school population.

Answer explanation

The sample is not random and not representative of the entire school population, as it only includes people involved in the musical, leading to bias.

I want to estimate the average number of hours SHS students spend playing video games. I sample all of my students. What kind of sampling bias is this?

• Non-response

• Voluntary

• Convenience

• Undercoverage

The parameter is a number describing the:

• population

• sample

• survey

• percent