STAT EXAM 1 - CHAP 1 Theory Q

In an experimental study

1 variable is measured and 2 groups are compared

What is the final step to be performed in the following mathematical expression? (ΣX)^2?

Square the sum of the scores

A characteristic, usually a numerical value, that describes a sample is called a _______.

statistic

Which of the following is an example of a continuous variable?

the amount of time to solve a problem

What is the first step to be performed in the following mathematical expression? (ΣX)^2

Add the scores

For a research study comparing attitude scores for males and females, participant gender is an example of what kind of variable?

a quasi-independent variable

Determining a person's reaction time (in milliseconds) would involve measurement on a(n) _____ scale of measurement.

ratio

A recent study reports that elementary school students who were given a nutritious breakfast each morning had higher test scores than students who did not receive the breakfast. For this study, what is the independent variable?

whether or not breakfast was given to the students

You are instructed to subtract four points from each score and find the sum of the resulting values. How would this set of instructions be expressed in summation notation?

Σ(X - 4)

You are instructed to subtract four points from each score, square the resulting value, and find the sum of the squared numbers. How would this set of instructions be expressed in summation notation?

Σ(X - 4)^2

In a correlational study

2 variables are measured and there is only 1 group of participants

The relationship between a statistic and a parameter is the same as the relationship between ______.

a sample and a population

If it is impossible to divide the existing categories of a variable, then it is an example of a _____ variable.

dependent

Statistical methods that organize, summarize, or simplify data are called _______.

descriptive statistics

After measuring two individuals, a researcher can say that Tom's score is 4 points higher than Bill's. The measurements must come from a(n) _______ scale.

interval or ratio

Determining the class standing (1st, 2nd, and so on) for the graduating seniors at a high school would involve measurement on a(n) _____ scale of measurement.

ordinal

Using letter grades (A, B, C, D, and E) to classify student performance on an exam is an example of measurement on a(n) _______ scale of measurement.

ordinal

A researcher is curious about the average monthly cell phone bill for high school students in the state of Florida. If this average could be obtained, it would be an example of a ______.

parameter

A researcher uses an anonymous survey to investigate the study habits of American college students. The group of American college students is an example of a(n)

population

A researcher is interested in the eating behavior of rats and selects a group of 25 rats to be tested in a research study. The group of 25 rats is an example of a ______.

sample

A researcher uses an anonymous survey to investigate the study habits of American college students. Based on the set of 56 surveys that were completed and returned, the researcher finds that these students spend an average of 4.1 hours each week working on course material outside of class. For this study, the set of 56 students who returned surveys is an example of a(n)

sample

Although a research study is typically conducted with a relatively small group of participants known as a _________, most researchers hope to generalize their results to a much larger group known as a _________.

sample; population

The average verbal SAT score for the entire class of entering freshmen is 530. However, if you select a sample of 20 freshmen and compute their average verbal SAT score you probably will not get exactly 530. What statistical concept is used to explain the natural difference that exists between a sample mean and the corresponding population mean?

sampling error

A researcher records the change in weight (gain or lost) during the first semester of college for each individual in a group of 25 freshmen, and calculates the average change in weight. The average is an example of a _______.

statistic

A researcher uses an anonymous survey to investigate the study habits of American college students. Based on the set of 56 surveys that were completed and returned, the researcher finds that these students spend an average of 4.1 hours each week working on course material outside of class. For this study, the average of 4.1 hours is an example of a(n) _______.

statistic

What is the final step to be performed when computing Σ(X - 2)^2?

sum the squared values

For an experiment comparing two methods for teaching social skill training to autistic children, the independent variable is _______ and the dependent variable is _______.

teaching methods; the social skills that are learned

A researcher conducts an experiment to determine whether moderate doses of St. Johns Wort have any effect of memory for college students. For this study, what is the independent variable?

the amount of St. Johns Wort given to each participant

Which of the following is an example of a discrete variable?

the gender of each student in a psychology class

What additional information is obtained by measuring two individuals on an interval scale compared to a ordinal scale?

the size of the difference