Psy 3110 Exam 1

What percent of the normal distribution is between z = -1 and z = 0? 68% 99.7% 13.6% 34%

34%

What percent of the normal distribution is within one standard deviation of the mean (i.e., |z| < 1)? cannot be calculated without additional information 1% 99.7% 68%

68%

Which measure of variation is LEAST sensitive to outliers? range IQR all are the same standard deviation

IQR

When a distribution of raw scores is converted to z-scores, the mean and standard deviation of the distribution will be... the same as they were before different but unpredictable M=1, SD=0 M=0, SD=1

M=0, SD=1

A frequency bar graph would be most appropriate for which measurement scales? Nominal or ordinal Interval or ratio Nominal or interval ordinal or ratio

Nominal or ordinal

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 negatively skewed Positively skewed unrepresentative bimodal

Positively skewed

The normal distribution is _____. asymmetrical a bell curve limited to three standard deviations from the mean skewed positively

a bell curve

In a positively skewed distribution, the extreme scores are _____. anything with an absolute value over 120 at the low end near the middle at the high end

at the high end

Which type of chart would be most appropriate for a nominal variable? histogram bar graph scatterplot boxplot

bar graph

One good use of the range is to... check for outliers help in calculations of the standard deviation separate groups of cases identify missing values

check for outliers

The variable that is measured as the outcome in an experiment is called the _____ variable. pattern dependent quasi-experimental independent

dependent

A bimodal distribution _____. cannot be used in inferential statistics is characteristic of income or house prices indicates an error in coding generally consists of two distinct populations

generally consists of two distinct populations

In an experiment, the variable that the researcher manipulates is called the _____ variable. observational skewed independent dependent

independent

What is the minimum level of measurement needed to calculate the mean? ordinal ratio interval nominal

interval

Which of the following is a defining characteristic of experiments? Laboratory setting Representative groups Biological measures Manipulation

manipulation

In a positively skewed distribution, which measure will generally have the highest value? mean median all are the same mode

mean

Which measure of central tendency is MOST influenced by outliers? all are the same mode mean median

mean

The three most common measures of central tendency are: variance, standard deviation, IQR mean, median, mode inferential, descriptive, explanatory nominal, ordinal, ratio

mean, median, and mode

Which measure of central tendency is most appropriate for skewed distributions? median mean no measure is appropriate mode

median

Which of these measures is LEAST affected by outliers? standard deviation mean median geometric mean

median

The normal distribution is uniform negatively skewed bimodal mesokurtic

mesokurtic

In a negatively skewed distribution, which measure will generally have the highest value? mean median mode all are the same

mode

A normal distribution has a value of skewness that is _____. near zero positive negative unmeasured

near zero

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

nominal

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

nominal

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

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 ordinal ratio interval

nominal

What is the minimum level of measurement needed to calculate the mode? ratio interval ordinal nominal

nominal

If a person has a z-score of 1 on a test, then their score is... one standard deviation above the mean the same as it was before one point above the raw score mean the only score in the distribution (i.e., n = 1)

one standard deviation above the mean

What is the minimum level of measurement needed to calculate the median? ratio ordinal interval nominal

ordinal

The larger group of people from which you got your observed group and to whom you wish to generalize your results is called the _____. database inferential group sample population

population

A histogram is appropriate when the data are _____. from a representative sample quantitative categorical ordinal

quantitative

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

ratio

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

ratio

The number of students enrolled at UVU each year is an example of which level of measurement? ratio interval nominal ordinal

ratio

Which level of measurement has a true zero point? ratio nominal ordinal interval

ratio

When a distribution of raw scores is converted to z-scores, the shape of the distributions. is unpredictable flattens out to a uniform distribution approaches a normal distribution remains the same

remains the same

The group of people from whom you actually gather data is called the _____. sample inferential group database population

sample

Which measure requires a degrees of freedom calculation? sample IQR population range population standard deviation sample variance

sample variance

What are the values of skewness and kurtosis for a normal distribution? Cannot be calculated without additional information skewness = 0 and kurtosis = 1 skewness = 0 and kurtosis = 0 skewness = 1 and kurtosis = 1

skewness = 0 and kurtosis = 0

If the formula for the population standard deviation were used with sample data, then result would be... identical too big too small impossible to calculate

too small

If scores in a data set are very different from each other, then the standard deviation... will be high will be biased for the sample cannot be calculated will be low

will be high