Chapter 1 exam review

Statistical methods are classified into which two major categories?

Descriptive and inferential

A researcher studies the factors that determine the number of cars owned by American families. The variable, number of cars, is an example of a ________ variable.

Discrete

A set of scores ranges from X= 18 to X = 91. If the scores are put into a group frequency distribution table with an interval width of 10 points, the top interval would be 91-100. True or false.

False

Statistical techniques that allow us to study samples and then make generalizations about the population from which they were selected are called what?

Inferential statistics

A researcher is curious about the average age of drivers in the city of Columbus. If he obtains a database of every driver in the city and calculate the average, this is an example of a

Parameter

Which of the following list the correct order for calculating Σ(X-1)^2

Subtract 1 from every term, square the result of each subtraction, and then add up the squares

A scientist to study in the effect of temperature on the ability of a plant to grow. She places for plants in a four different temperatures. All plants are given the same amount of water and light each day. She measures the height of each plant at the end of the month. Which of the following describes the dependent and independent variables?

The dependent is the plant height; the independent variable is the room temperature

Which is an example of a scientist being interested in a correlation? 1) determining the average height of males and females in England 2). Determining if there is a relationship between and insects wingspan and it's weight 3) determining the average GPA in the freshman and senior classes that Valley view high school

Two only

For which situation is n= Σx?

When the values of x are all 1

Which of the following is equivalent to Σ(x-1)^2?

Σx^2 + 2 Σx + Σ1

Which of the following to provide an operational definition of shyness? 1) the number of people interacted with over the course of a day 2) the amount of time spent alone 3) the number of times eye contact is made in the course of a conversation

1, 2, And 3

If we are looking at the average IQ of all Americans by looking at a sample of 50 people, which of the following is true? 1) The average IQ of the sample could be greater than the average IQ the population 2) average IQ of the sample could be smaller than average IQ of the population 3) The average IQ of the sample must be the same as the average IQ of the population

1 and 2 only

Which of the following is true? 1) all ratio scales are interval scales 2) all ratio scales are nominal scales 3) all interval scales are ratio scales 4) all nominal scales are ratio scales

1) all ratio scales are interval scales

When measuring weight to the nearest half ounce, what are the real limits for a score of 23 ounces?

22.75 and 23.25

John and Aaron are looking at a series of quiz scores. The quiz is a short quiz on which students could score 0, 0.5, one, 1.5, two, 2.5, or three points. John claims that the quiz score is a discrete variable, and Aaron claims that is a continuous variable. Who is correct and why?

John is correct because there are finite number of scores with no possible values in between those scores

Two students, Lauren and Mary, are studying the average age at death of females in the town of Mobile Alabama in the year 2011. They are able to obtain all of the female death records from Mobile for the year 2011. Lauren claims that this set of records represent the population for their study. Mary claims that it is only a sample. Who is correct and why?

Lauren is correct because the study is only about female deaths in Mobile during 2011

Researchers are conducting a study to determine the effect of caffeine on memory among Americans. A sample of 100 individuals is given a list of 20 words to look at and remember over the course of 24 hours. Which of the following uses correct notation?

N=100

What are the values of n and ΣX for the following scores: 3,3,4,6?

N=4, ΣX=16

In what kind of study we find a quasi-independent variable?

Non-experimental studies

A recent study comparing salaries for recent college graduate in Spain versus France reports that the recent graduates in France are more than those in Spain. What research design did the Study use?

Nonexperimental

Which of the following is not required for a proper experiment?

Quasi independent variable