BESC 3010 chapter 1-5

Which measure of central tendency is most appropriate for skewed distributions?

Median

Which measure of central tendency works for nominal variables?

Mode

Which of these measures of central tendency works for nominal variables?

Neither the mean nor the median works for nominal variables.

For a distribution with M = 100 and SD = 15, what is the z-score for a raw score of 112?

+0.8

Which z-score is closest from the mean of its distribution?

-0.9

In a data set with a mean of 50 and a standard deviation of 10, what z-score would a raw score of 35 have?

-1.5

In most distributions, nearly all (more than 99%) of the sample scores will be within what range of z-scores?

-3 to +3

For a normal distribution, kurtosis is...

0

If a distribution of 144 scores with a mean of 52 and a standard deviation of 12 is standardized, then the new distribution's mean will be _____.

0

In a bimodal distribution with a mean of 80 and standard deviation of 20, what would the z-score be for a raw score of 80?

0

In a unimodal distribution with a mean of 80 and standard deviation of 20, what would the z-score be for a raw score of 80?

0

What is the value of kurtosis for a normal distribution?

0

What is the value of skewness for a normal distribution?

0

No matter what the shape of a distribution, if it is converted to z-scores, then its mean will be...

0.

What is the population variance for the following data? 4, 5, 5, 6

0.5

No matter what the shape of a distribution, if it is converted to z-scores, then its standard deviation will be...

1

What is the interquartile range (IQR) for the these data: 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 4+

1

What is the sample standard deviation for the following data? 2, 2, 3, 4, 4

1

If the mean of a sample is 5 and the standard deviation is 2, then what is the z-score for a raw score of 8?

1.5

What is the sample standard deviation for this data set? 3, 4, 2, 4, 7

1.87

Which z-score is furthest from the mean of its distribution?

1.9

What is the frequency of 1 in the following data set? 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 5

2

What is the median for these data? 5, 1, 1, 3, 2

2

What is the mode for the following data set? 1 2 2 2 2 2 3 3 3 3 4 4 4 5 5 5 5 6 6 7 7+

2

What is the mode for these data? 3, 1, 2, 5+, 2, 4

2

What is the IQR for this data set? 6, 4, 6, 6, 1, 6, 3, 4

2.5

What is the median for these data? 3, 1, 2, 5+, 2, 4

2.5

If a person has a z-score of +2, what would their raw score be in a distribution with a mean of 20 and a standard deviation of 3?

26

What is the frequency of 4 in the following data set? 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 5

3

What is the frequency of 4 in the following data set?1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 5

3

What is the mean for these data? 3, 1, 2, 5, 3, 4

3

If a distribution has a mean of 50 and a standard deviation of 5, then a raw score of 68 would have a z-score of...

3.6

What percent of the normal distribution is between z = -1 and z = 0?

34%

What is the frequency of 2 in the following data set: 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 5

4

What is the mean for these data? 4, 2, 3, 6, 4, 5

4

What is the median for the following data set? 1 2 2 2 2 2 3 3 3 3 4 4 4 5 5 5 5 6 6 7 7+

4

What is the population variance for this data set? 4, 1, 6, 1

4.5

What is the frequency of 3 in the following data set? 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 5

5

What is the range for the following dataset: 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 3, 3, 4, 5

5

What is the range for this data set? 5, 1, 2, 6, 5

5

What percent of the normal distribution has |z| < 1 (i.e., an absolute value less than 1)?

68%

What percent of the normal distribution is within one standard deviation of the mean (i.e., |z| < 1)?

68%

If a person got a z-score of -2 on a test that had a mean of 80 and a standard deviation of 5, then what was their raw score?

70

For a distribution with M = 80 and SD = 6, what is the X score for a person who has a z-score of -1.5?

71

What percent of a normal distribution is below a z-score of +1?

84%

In a normal distribution, what percent of the distribution is within between z = -3 and z = +3?

99.7%

In a normal distribution, which measure of central tendency has the highest value?

All are the same

For which levels of measurement can you calculate the mode?

Both ordinal and interval

Which measure of variation is LEAST sensitive to outliers?

IQR

When a distribution of raw scores is converted to z-scores, the mean and standard deviation of the distribution will be...

M = 0, SD = 1.

Which of the following is a defining characteristic of experiments?

Manipulations

A frequency bar graph would be most appropriate for which measurement scales?

Nominal or ordinal

When data are negatively skewed, which measure of variability is most appropriate?

Quartiles (such as the interquartile range)

When open-ended scores are present in the data, which measure of variability is most appropriate?

Quartiles (such as the interquartile range)

What is the highest level of measurement?

Ratio

Which measure requires a degrees of freedom calculation?

Sample variance

For a normal distribution, which measure of variability is most efficient (in the statistical sense)?

Standard deviation

In a positively skewed distribution, which measure of central tendency has the highest value?

The mean

Which measure of central tendency is always influenced by outliers?

The mean

Which of these measures is MOST affected by outliers?

The mean

Which of the following measures of central tendency can be used with data on the ratio level of measurement?

The mean or the mode

What does the symbol σ2 stand for?

The population variance

What is the relationship between the standard deviation and the variance?

The standard deviation is the square root of the variance

What does the label "Q2" refer to?

What does the label "Q2" refer to?

For a study to be considered an experiment, it must have...

a manipulation.

Which is bigger: a sample or a population?

a population

Compared to a mesokurtic distribution, the tails of a leptokurtic distribution...

are longer.

A histogram is not appropriate when the data are...

at the nominal or ordinal level of measurement.

Which type of chart would be most appropriate for a nominal variable?

bar graph

When a histogram or polygon chart for a quantitative variable has two distinct peaks, then the distribution is referred to as

bimodal

A distribution that has two distinct peaks is referred to as...

bimodal.

A distribution with two distinct peaks can be described as...

bimodal.

What is the mean for these data? 3, 1, 2, 5+, 2, 4

cannot be calculated

What is the range for this data set? 5, 3, 7+, 1, 4

cannot be calculated

One good use of the range is to...

check for outliers.

The variable that is measured as the outcome in an experiment is called the _____ variable.

dependent

Inferential statistics are typically contrasted with _____ statistics.

descriptive

A question that asks a person how strong their motivations for religious participation are using a 1-7 rating scale is at _____ level of measurement.

either the ordinal or the interval

A score's frequency is determined by...

how often it occurs in the data set.

In an experiment, the variable that the researcher manipulates is called the _____ variable.

independent

If the number of games a team has lost in a season is subtracted from the number of games that they won in that season, the resulting variable would be at the _____ level of measurement.

interval

Temperature in celsius or Fahrenheit (but not Kelvin) is measured at which level of measurement?

interval

What is the minimum level of measurement needed to calculate the mean?

interval

The standard normal distribution...

is a bell curve with M = 0 and SD = 1

For a normal distribution, skewness...

is equal to 0.

A uniform distribution...

is platykurtic

A narrow distribution that is sharply pointed in the middle and that has many outliers is called...

leptokurtic

If a web marketer compares the effectiveness of two online ads in getting clicks by gathering data from 3 million Internet shoppers, the population of interest is...

ll Internet shoppers.

In a positively skewed distribution, which measure will generally have the highest value?

mean

Which measure of central tendency is MOST affected by outliers?

mean

Which measure of central tendency is MOST influenced by outliers?

mean

The three most common measures of central tendency are:

mean, median, mode

Which of these measures is LEAST affected by outliers?

median

The normal distribution is...

mesokurtic

In a negatively skewed distribution, which measure will generally have the highest value?

mode

Which measure of central tendency is LEAST efficient?

mode

What is the degrees of freedom for the sample variance?

n - 1

Compared to a mesokurtic distribution, the peak of a leptokurtic distribution is...

narrower and higher.

A normal distribution has a value of skewness that is _____.

near zero

A normal distribution generally has _____ skew.

no

A question that asks a person which religion (if any) they identify with is at the _____ level of measurement.

nominal

A variable that classifies people into racial or ethnic groups is what level of measurement?

nominal

If a person's sex is coded as Male = 0 or Female = 1, then that variable is at the _____ level of measurement.

nominal

If a person's sex is recorded as "Male" or "Female," then that variable is at the _____ level of measurement.

nominal

The only level of measurement that does not place scores or categories into order (and is therefore the lowest level of measurement) is the _____ level of measurement.

nominal

The respondent's gender is typically recorded as a(n) _____ variable.

nominal

What is the minimum level of measurement needed to calculate the mode?

nominal

Compared to a mesokurtic distribution, the peak of platykurtic distribution is...

not as high

If a person has a z-score of 1 on a test, then their score is...

one standard deviation above the mean.

A univariate analysis typically focuses on...

one variable at a time

A question that asks whether a person believes they are more creative, less creative, or just as creative as other people is at the _____ level of measurement.

ordinal

What is the minimum level of measurement needed to calculate the median?

ordinal

A sample is a part of a larger...

population

A distribution such as income that has most of the people at the bottom or middle but a few people with extremely high scores, is referred to as...

positively skewed.

If a positively skewed distribution with a mean of 100 and a standard deviation of 15 is standardized, then the shape of the new distribution will be...

positively skewed.

A histogram is appropriate when the data are...

quantitative

Which measure of variation is most influenced by outliers?

range

A question that asks how many times a person attends religious services each year is at the _____ level of measurement.

ratio

A variable that records how many seconds it take for a person to spell a word backwards is at the _____ level of measurement.

ratio

The amount of time that a person spends on social media each week in minutes is a(n) _____ variable.

ratio

The highest level of measurement (i.e., the one that contains the most information) is the _____ level of measurement.

ratio

The number of students enrolled in a school each year is an example of which level of measurement?

ratio

Which level of measurement has a true zero point?

ratio

When a distribution of raw scores is converted to z-scores, the shape of the distributions...

remains the same.

If a researcher is able to survey 99% of all students enrolled in statistics classes at a college, then that researcher has gathered data from a(n)...

sample

What are the values of skewness and kurtosis for a normal distribution?

skewness = 0 and kurtosis = 0

A population can never be...

smaller than one of its samples.

Which of the following is NOT a measure of central tendency?

standard deviation

In an experiment that looks at the effect of different teaching methods on student learning, the independent variable is...

teaching method.

One visual difference between a bar chart and a histogram is that in a histogram...

the adjacent bars touch but in a bar chart they are separate.

A bivariate analysis typically focuses on...

the association of two variables

If the formula for the population standard deviation were used with sample data, then result would be...

too small

When a histogram for a quantitative variable has only one distinct peak, then the distribution is referred to as...

unimodal.

When scores in a data set are very close to one another, then the variance...

will be close to 0.

If scores in a data set are very different from each other, then the standard deviation...

will be high.