Practice Exam #1

Given this data [1, 1, 6, 7, 2, 3, 10, 0, 1] what is the median? Mode?

Median = 2 Mode = 1

1. Match the example on the left with the variable type on the right a. Time b. T-Shirt size c. Number of patients d. Quantitative Discrete e. Qualitative f. Quantitative Continuous

a. & f. b. & e. c. & d.

In a distribution of μ = 70 and σ = 6, which of the following z-scores corresponds to a score of X = 63? a. -1.17 b. 1.02 c. -1.02 d. 1.17

a. -1.17

In a given sample, you have a SS = 50 and an N = 6. What is the standard deviation? a. 3.16 b. 10 c. 8.33 d. 2.89

a. 3.16

What measure of central tendency is LEAST affected by outliers? MOST affected? a. Mode, Mean b. Mean, Median c. Median, Mean d. Mean, Mean

a. Mode, Mean

Which of these statements about central tendency is NOT true? a. The mean is always the best choice for any distribution b. The mean, median and mode are all the same in a normal distribution c. Median is the second most affected by outliers d. It is reported alongside variance in APA format

a. The mean is always the best choice for any distribution

Which is the closest to a normal distribution a. Leptokurtosis b. Mesokurtosis c. Platykurtosis d. sadykurtotis

b. Mesokurtosis

Jenna has a bag filled with different colored marbles. The following diagram shows the frequencies of each color. What measure of central tendency should be used? a. Median b. Mode c. Mean d. All of the above

b. Mode

Which scale of measurement is a Likert (satisfaction) scale? a. Nominal b. Ordinal c. Interval d. Ratio

b. Ordinal

Z-scores are calculated in terms of a. Mean b. Standard deviation c. X-values d. Range

b. Standard deviation

Which of the following is NOT true about standard deviation? a. Standard deviation is always positive b. Standard deviation is the best measure of variability when there are outliers c. Standard deviation will not be changed when adding or subtracting a constant to scores d. Standard deviation measures how spread out or clustered together scores are in a distribution

b. Standard deviation is the best measure of variability when there are outliers

A researcher wants to know if excessive soda drinking contributes to weight gain. They instruct half of the participants to drink only water for two months, while the other half is instructed to drink only full-sugar soda. What is the dependent variable? a. Type of drink b. Weight gain c. Excessive Soda drinking d. Water

b. Weight gain

According to the empirical rule, what percent of scores will be within 2 standard deviations from the mean? a. 68% b. 75% c. 95% d. 99.7%

c. 95%

In a negatively skewed distribution of goals scored during a soccer game, Ashley scored the mode, Jill scored the median, and Stephanie scored the mean. Who had the highest score? (Try drawing it out) a. Jill b. Stephanie c. Ashley d. Cannot be determined from the given information

c. Ashley

What type of frequency graph is the normal distribution bell curve approximating? a. Bar graph b. Pie Chart c. Histogram d. All of the above

c. Histogram

A z-score of -1.37 indicates that the X-value or raw score: a. Is located 1.37 standard deviations above the mean b. Is located 1.37 standard deviations to the right of the mean c. Is located 1.37 standard deviations below the mean d. Both b and c

c. Is located 1.37 standard deviations below the mean

What is NOT true about a normal distribution bell curve a. It is symmetrical b. It is an approximation of the population frequencies c. It is naturally a little skewed d. It has the same values for all measures of central tendency

c. It is naturally a little skewed

Which of the following is NOT a measure of variability a. Interquartile range b. Standard Deviation c. Mean d. Range

c. Mean

What is sampling error? a. Human error b. When an unrepresentative sample is selected from the population c. The difference between the population parameter and the sampling statistic d. Standard Deviation divided by n

c. The difference between the population parameter and the sampling statistic

Which of the following is true about the distribution after converting every X-score into a z-score? a. The mean will always equal zero b. The shape of the distribution will remain the same c. The standard deviation will always equal one d. All of the above

d. All of the above

Which type of frequency graph is appropriate for a qualitative variable? a. Histogram b. Pie Chart c. Bar Graph d. b & c

d. b & c