Statistics for the Behavioral Sciences Hypothesis Testing with z Tests Susan A. Nolan and Thomas E. Heinzen Statistics for the Behavioral Sciences Second Edition Chapter 7: Hypothesis Testing with z Tests iClicker Questions Copyright © 2012 by Worth Publishers

Chapter 7 The z test is: a) another way to calculate the mean. b) the simplest of the hypothesis tests. c) a non-parametric test. d) used only with data that is composed of negative numbers.

Chapter 7 (Answer) The z test is: a) another way to calculate the mean. b) the simplest of the hypothesis tests. c) a non-parametric test. d) used only with data that is composed of negative numbers.

Chapter 7 2. If Laura received a z score of 1 for her performance on a standardized math test, approximately what percentage of scores is below her score? a)  34.13% b)  -34.13% c)   84.13% d)  -84.13%

Chapter 7 (Answer) 2. If Laura received a z score of 1 for her performance on a standardized math test, approximately what percentage of scores is below her score? a)  34.13% b)  -34.13% c)  84.13% d)  -84.13%

Chapter 7 3.  From the example above, what percentage of scores are between Laura’s z score and the mean? a)  34.13% b)  -34.13% c)  -84.13% d)  84.13%

Chapter 7 (Answer) 3.  From the example above, what percentage of scores are between Laura’s z score and the mean? a)  34.13% b)  -34.13% c)  -84.13% d)  84.13%

Chapter 7 4. A z score has a known mean and standard deviation. What are they? a)    Mean = 50, SD=2.0 b)    Mean = 0, SD=3 c)    Mean = 50, SD= 1 d)   Mean = 0, SD = 1

Chapter 7 (Answer) 4. A z score has a known mean and standard deviation. What are they? a)    Mean = 50, SD=2.0 b)    Mean = 0, SD=3 c)    Mean = 50, SD= 1 d)   Mean = 0, SD = 1

Chapter 7 5. Roberta scored in the 85th percentile on a standardized test of reading ability. What is Roberta’s associated z score? a) -1.04 b) 2.3 c) 3.1 d) 1.04

Chapter 7 (Answer) 5. Roberta scored in the 85th percentile on a standardized test of reading ability. What is Roberta’s associated z score? a) -1.04 b) 2.3 c) 3.1 d) 1.04

Chapter 7 6. If we obtain a z score of 2.5, what is our raw score for a given population mean of 800 and a standard deviation of 100? a) 1000 b) 1600 c) 900 d) 1050  

Chapter 7 (Answer) 6. If we obtain a z score of 2.5, what is our raw score for a given population mean of 800 and a standard deviation of 100? a) 1000 b) 1600 c) 900 d) 1050  

Chapter 7 The figure below demonstrates the concept of converting a given percentile to a raw score for a student who scored in the 63rd percentile. Thirteen percent corresponds to the associated percentage that results from subtracting the area below the mean from the 63rd percentile. What is the associated z score? a) 50 b) 0.33 c) 13 d) 87

Chapter 7 (Answer) The figure below demonstrates the concept of converting a given percentile to a raw score for a student who scored in the 63rd percentile. Thirteen percent corresponds to the associated percentage that results from subtracting the area below the mean from the 63rd percentile. What is the associated z score? a) 50 b) 0.33 c) 13 d) 87

Chapter 7 8. What are the three assumptions for hypothesis testing? a) independent variable is measured on an interval scale, participants are based on a convenience sample, and the population distribution is approximately normal b) extraneous variables are controlled for, random selection, and random assignment c) dependent variable is measured on an interval or ratio scale, participants are randomly selected, and population distribution is approximately normal d) variables are all continuous, variables are measured on a ration scale of measurement, and participants are randomly selected

Chapter 7 (Answer) 8. What are the three assumptions for hypothesis testing? a) independent variable is measured on an interval scale, participants are based on a convenience sample, and the population distribution is approximately normal b) extraneous variables are controlled for, random selection, and random assignment c) dependent variable is measured on an interval or ratio scale, participants are randomly selected, and population distribution is approximately normal d) variables are all continuous, variables are measured on a ration scale of measurement, and participants are randomly selected

Chapter 7 9. _______________ are inferential statistical analyses based on a set of assumptions about the population. a) Standardized tests b) Non-standardized tests c) Parametric tests d) Nonparametric tests

Chapter 7 (Answer) 9. _______________ are inferential statistical analyses based on a set of assumptions about the population. a) Standardized tests b) Non-standardized tests c) Parametric tests d) Nonparametric tests

Chapter 7 10. All of the following are among the six steps of hypothesis testing EXCEPT: a) identifying the populations, comparison distribution, and assumptions. b) determining the characteristics of the comparison distribution. c) determining critical values, or cutoffs. d) randomly selecting participants from the population.

Chapter 7 (Answer) 10. All of the following are among the six steps of hypothesis testing EXCEPT: a) identifying the populations, comparison distribution, and assumptions. b) determining the characteristics of the comparison distribution. c) determining critical values, or cutoffs. d) randomly selecting participants from the population.

Chapter 7 When researchers say that a result is statistically significant they mean: a) the data differ from what we would expect by chance if there were, in fact, no actual difference. b) the finding must be important and meaningful. c) the result is huge. d) the result is important and meaningful to them, but necessarily to other researchers.

Chapter 7 (Answer) When researchers say that a result is statistically significant they mean: a) the data differ from what we would expect by chance if there were, in fact, no actual difference. b) the finding must be important and meaningful. c) the result is huge. d) the result is important and meaningful to them, but necessarily to other researchers.

Chapter 7 12. A researcher hypothesizes that there is a significant relationship between stress and fatigue. Specifically, he hypothesizes that, as stress increases, fatigue levels will also increase. This example best illustrates what type of hypothesis test? a) null hypothesis test b) one-tailed test c) two-tailed test d) non-directional test  

Chapter 7 (Answer) 12. A researcher hypothesizes that there is a significant relationship between stress and fatigue. Specifically, he hypothesizes that, as stress increases, fatigue levels will also increase. This example best illustrates what type of hypothesis test? a) null hypothesis test b) one-tailed test c) two-tailed test d) non-directional test  

Chapter 7 A researcher hypothesizes that there is a significant relationship between stress and fatigue. Specifically, he hypothesizes that, as stress increases, fatigue levels will change. This example best illustrates what type of hypothesis test? a) null hypothesis b) one-tailed test c) two-tailed test d) uni-directional test  

Chapter 7 (Answer) A researcher hypothesizes that there is a significant relationship between stress and fatigue. Specifically, he hypothesizes that, as stress increases, fatigue levels will change. This example best illustrates what type of hypothesis test? a) null hypothesis b) one-tailed test c) two-tailed test d) uni-directional test  

Chapter 7 All of the following are ways that researchers clean up dirty data EXCEPT: a) assign the mode or the men for that variable based on the other participants’ results. b) assign the mode or the mean from the participant’s own responses if there are similar items in the database. c) assign a random number that is within the range of possible numbers for that data set. d) assign a random number that is outside the range of numbers for the data set so it won’t be confused with the real data.

Chapter 7 (Answer) All of the following are ways that researchers clean up dirty data EXCEPT: a) assign the mode or the men for that variable based on the other participants’ results. b) assign the mode or the mean from the participant’s own responses if there are similar items in the database. c) assign a random number that is within the range of possible numbers for that data set. d) assign a random number that is outside the range of numbers for the data set so it won’t be confused with the real data.