# Statistics Question

The questions are structured so that a single letter, word, or number will suffice. Computational

questions are arranged so that partial credit can be given for each step answered correctly.

Always use the following model to submit your answers to the questions.

EXAMPLE:

Your name:

Midterm Exam:

Answers

Q1 C

Q2 B

Q3 A, etc.

If the question requires computation, do the calculations and then give the correct

values as follows:

(Always hold all decimal values through your computations, and round final

answers to at least two decimal places)!

Q4 7

Q5 4

Q6 22, etc.

If the question is a fill in the blank, just put in the appropriate word(s) as follows:

Q7 statistics

Q8 dependent variable, etc

Psychology 1110– Mid-term Exam

Elementary Statistical Reasoning—Online

Dr. Craig C. McCarthy

-The exam will be graded out of 100 total points

(25% of your grade)

-There are 5 additional short answer questions

2 (total) extra credit points.

Write answers for the following and submit them via email according to the schedule in the

course syllabus. Be sure your answers are contained in the body of your message. Do NOT send

them as attachments.

Send your answers to Mid-term Exam to the instructor: mccartc1@ohio.edu

The questions are structured so that a single letter, word, or number will suffice. Computational

questions are arranged so that partial credit can be given for each step answered correctly.

Always use the following model to submit your answers to the questions.

EXAMPLE:

Your name:

Midterm Exam:

Answers

Q1 C

Q2 B

Q3 A, etc.

If the question requires computation, do the calculations and then give the correct

values as follows:

(Always hold all decimal values through your computations, and round final

answers to at least two decimal places)!

Q4 7

Q5 4

Q6 22, etc.

If the question is a fill in the blank, just put in the appropriate word(s) as follows:

Q7 statistics

Q8 dependent variable, etc.

1

Q1:

The goal(s) of statistical procedures are to

A. predict or infer what might happen in the future

B. describe what has happened

C. neither A nor B is correct

D. both A and B are correct

Q2:

Parameter is to population as _________ is to sample

A. descriptive

B. statistic

C. margin of error

D. inferential

Q3:

The concept of generalizing from a few observations to an entire group is central to the

area of

A. inferential statistics

B. descriptive statistics

Q4:

Statistical questions tend to fall into what two main categories?

A. samples or populations

B. relationships or categories

C. relationships or differences

D. differences or categories

E. none of the above

Q5:

An example of descriptive statistics would be

A. based on previous data, prediction of the expected number of fans who will

show up to a Tuesday night professional baseball game

B. calculating the number of people who actually showed up to a professional

baseball game

For the following 4 questions (Q6 to Q9) identify the scale of measurement.

Use the following system:

A. nominal

B. ordinal

C. interval

D. ratio

Q6:

Gender

Q7:

The amount of time it takes you to shower

Q8:

The Fahrenheit temperature scale

Q9:

Students voting for their preferred professors by ranking them

2

For the following 2 questions (Q10 to Q11) identify the following variables as either

measurement or categorical.

Use the following system:

A. measurement

B. categorical

Q10: Academic letter grade (i.e. A, A-, B+, B, and so forth)

Q11: The number of points earned on a statistics exam

For the following 2 questions (Q12 to Q13) identify the following variables as either

discrete or continuous.

Use the following system:

A. discrete

B. continuous

Q12: The time elapsed since last Christmas

Q13: The number of cats you own

The following 4 questions (Q14 to Q17) are based on the following situation:

A biologist was investigating the number of eggs laid by snakes. She believes there is a

difference between Rattlesnakes and King Cobras.

Q14: What is the dependent variable?

__________

Q15: What is the independent variable?

__________

Q16: Is the dependent variable discrete or continuous?

__________

Q17: What is the scale of measurement of the dependent variable?

__________

Q18: A researcher was investigating whether gender, age of the student, and GPA of the

student had a bearing on how much alcohol the average Ohio University student would drink on

a typical weekend. How many dependent variables are involved with this research?

A. one

B. two

C. three

D. four

3

The following 2 questions (Q19 to Q20) are based on the following situation:

A quality control supervisor measures the quality of steel ingot on a scale from 0 to 10.

He designs an experiment in which three different temperatures and five different pressures are

utilized, with 20 ingots produced at each Temperature-Pressure combination.

Q19: What is/are the dependent variable(s)?

A. quality of steel

B. temperature

C. pressure

D. two of the above are correct

Q20: What is/are the independent variable(s)?

A. quality of steel

B. temperature

C. pressure

D. two of the above are correct

The following 4 questions (Q21 to Q24) are based on the following article:

PER CAPITA INCOME OF U.S. SPRINKS RELATIVE TO OTHER COUNTRIES

(from UTTS, 2005, page 24)

An independent research group, the Institute for Foreign Investment, has noted that the

per capita income of Americans has been shrinking relative to some other countries. Using per

capita income figures from the World Almanac and exchange rates from last Friday’s financial

pages, the organization warned that per capita income for the United States has risen only 10%

during the past 5 years, whereas per capita income for certain other countries has risen 50%. The

researchers concluded that more foreign investment should be allowed in the United States to

bolster the sagging economy.

Use the following system to answer Q21 to Q24:

A. Component 1

B. Component 2

C. Component 3

D. Component 4

E. Component 5

F. Component 6

G. Component 7

Q21: What is one of the three components that (according to Utts) was BOTH relevant and

NOT properly discussed within the article?

4

Q22: What is the second of the three components that (according to Utts) was BOTH relevant

and NOT properly discussed within the article?

Q23: What is the third of the three components that (according to Utts) was BOTH relevant

and NOT properly discussed within the article?

Q24: According to Utts, which of the components was considered a ‘major problem’?

For the following 3 questions (Q25 to Q27) identify which one of the seven pitfalls when

asking a question applies to each of the following potential survey questions.

Use the following system:

A. Deliberate bias

B. Unintentional bias

C. Desire to please

D. Asking the uninformed

E. Unnecessary complexity

F. Ordering of questions

G. Confidentiality and anonymity

Q25: Do you agree that this huge win tonight has to be the biggest win of your 25-year

collegiate coaching career?

Q26: Do you use drugs?

Q27: Don’t you think that Ohio University students shouldn’t receive consequences from the

university for illegal behavior that doesn’t occur on campus?

Q28: “Please list the most important factors associated with academic success here at Ohio

University”. This is an example of

A. a closed-ended question/statement

B. an open-ended question/statement

C. a common pitfall when asking survey questions/statements

D. deliberate bias

Q29: A survey was conducted with 900 Ohio University students. One of the conclusions from

this survey was that 55% of the students believed the academics at Ohio University were ‘very

strong’. Based on these sample results, are you convinced that a majority (i.e. over 50%) of all

students believe the academics are ‘very strong’?

A. Yes

B. No

5

Q30: ___________ refers to unpredictable errors or discrepancies that are not easily explained.

A. Reliability

B. Variability

C. Validity

D. Bias

Q31: A professor’s weight scale is always 10 pounds too light. Which of the following best

describes the scale’s measurements of weight?

A. unreliable

B. validity

C. variability

D. biased

For the following 4 situations (Q32 to Q35) identify which sampling method should be

utilized by the researcher.

Use the following system:

A. simple random sampling

B. systematic random sampling

C. cluster sampling

D. stratified sampling

E. random digit dialing

F. multistage sampling

Q32: Ohio University wants to investigate satisfaction for freshmen students at the end of their

first year of classes. Therefore, the university uses a computer and selects every 10th student from

an alphabetical list of approximately 4000 names.

Q33: In a survey of Athens county voters, a researcher divides her sampling frame into age

brackets (e.g., 18-35, 36-50, 51-75, etc.) and randomly samples 100 individuals from each age

bracket.

Q34: United Airlines wants to investigate customer satisfaction from their passengers.

Therefore, the researchers for United divided the country into 4 regions; the West, the Midwest,

the South, and the East. Random samples of 3 specific flights were chosen in each region and

every passenger on those flights was asked to complete a satisfaction questionnaire.

Q35: A researcher was interested in researching the volunteer hours of sorority sisters at Ohio

University. She obtains a list of all 14 sororities. From the list she selects 5 sororities and

samples everybody in each of those 5 sororities.

6

The following 5 questions (Q36 to Q40) are either “True” or “False”

Q36: UTTS considers ‘Getting a volunteer sample’ a “difficulty in sampling”.

Q37: ‘Experiments’ measure the effect of manipulating the environment in some way—then

measure the result on the feature being manipulated on an outcome.

Q38: A ‘meta-analysis’ is an in-depth examination of one or a small number of individuals.

Q39: ‘Case studies’ are used to make inferences about larger populations.

Q40: A ‘census’ is a survey in which the entire population is measured.

The following 6 summation questions (Q41 to Q46) are based on the table below:

X

Y

7

-4

3

0

-2

6

-1

3

4

4

Q41: ΣXΣY

Q42: Σ(X – 2Y)

Q43: ΣY2 + 10

Q44: (ΣX)2 + ΣY

Q45: ΣXY

Q46: (ΣX) – (ΣY)

7

The following 6 questions (Q47 to Q52) are based on the histogram below:

5

Frequency

4

3

2

1

0

1

2

3

4

5

Quiz Score

Q47: What is the sample size?

Q48: What score is associated with the 70th percentile?

Q49: What percentile with a score of 1.5.

Q50: What percentage of the people scored between 2.5 and 4.5?

Q51: The histogram is

A. negatively skewed

B. positively skewed

C. normally distributed

D. none of the above

Q52: The histogram is

A. unimodel

B. bimodal

C. modality

D. a good example of outliers

8

The following 7 questions/computations (Q53 to Q59) are based on a sample summarized in

the stemplot below:

Stem | Leaf

1

|369

2

|022288

3

|0

Compute:

Q53: mean

Q54: median

Q55: mode

Q56: range

Q57: interquartile range

Q58: variance

Q59: standard deviation

The following 1 question (Q60) is either “True” or “False”

Q60: A grouped frequency distribution is generally a poor choice for displaying data.

The following 11 questions (Q61 to Q71) are based on the following summarized research:

(you will need your z-tables from Howell to complete many of these questions)

A psychologist studied self-esteem scores and found the data set to be normally

distributed with a mean of 60 and a standard deviation of 5.

Part A**What raw score cuts off the bottom 33% of this distribution?

Steps:

Q61: What is the z-score that cuts off the bottom 33% of this distribution?

Q62: What is the raw score that cuts off the bottom 33% of this distribution?

9

Part B**What percentage of the scores is between 65 and 70?

Steps:

Q63: What is the z-score that corresponds to the raw score of 65?

Q64: What is the z-score that corresponds to the raw score of 70?

Q65: What percentage of the scores is between 65 and 70?

Part C:**A raw score of 57.5 is associated with what percentile?

Steps:

Q66: What is the z-score associated with a raw score of 57.5?

Q67: A raw score of 57.5 is associated with what percentile?

Part D:**What raw scores mark the middle 95% of this distribution?

Steps:

Q68: What are the z-scores that mark the middle 95% of this distribution?

Q69: What is the raw score below the mean?

Q70: What is the raw score above the mean?

Part E:**What is the median of this distribution?

Q71: What is the median of this distribution?

Q72: In a positively skewed distribution, Alice scored the mean, Betty scored the median, and

Claire scored the mode. Who had the lowest score?

A. Alice

B. Betty

C. Claire

D. All three scored approximately the same

Q73: In a normal distribution, Alice scored the mean, Betty scored the median, and Claire

scored the mode. Who had the lowest score?

A. Alice

B. Betty

C. Claire

D. All three scored approximately the same

10

Q74: The z-distribution always has a mean of _____ and a standard deviation of _____.

A. 1; 0

B. 0; 0

C. 0; 1

D. 1;1

Q75: A test score of 84 was transformed into a standard score of –1.5. If the standard deviation

of test scores was 4, what is the mean of the test scores?

A. 78

B. 89

C. 90

D. 88

Q76: The standard deviation for the sample numbers 8, 9, and 10 is

A. –3.0

B. 0.0

C. .67

D. 1.0

Q77: A university administrator randomly selected 10 freshmen and 10 seniors and asked them

how satisfied they are with life at Ohio University on a 1 (not at all satisfied) to 9 (very satisfied)

scale. The administrator’s date is below:

Mean

Variance

Freshmen

3

10

Seniors

8

1

These results seem to indicate that:

A. freshmen agree more with each other about their life satisfaction than do

seniors

B. seniors agree more with each other about their life satisfaction than do

freshmen

C. all freshman tend to be satisfied with life

D. freshmen and seniors experience equal life satisfaction

E. none of the above are accurate

Q78: A sample of data has a standard deviation of 10. If you were to divide all the scores in the

date set by a factor of two (2), what would the new standard deviation be?

A. 10

B. 5

C. 2.5

D. none of the above

The following 2 questions (Q79 to Q80) are either “True” or “False”

Q79: The variance for a set of data can be a negative value.

Q80: The two parameters that completely characterize a standardized normal distribution

are “μ” and “σ”.

11

The following 12 questions (Q81 to Q92) are based on the summarized table below:

Hours Studied

1

2

3

5

ΣX = 11

X2

1

4

9

25

Y2

9

25

49

81

Score on Quiz

3

5

7

9

ΣX2 = 39

ΣY = 24

ΣY2 =164

XY

3

10

21

45

ΣXY =79

Q81: What is the predictor variable?

Q82: What is the criterion variable?

Part A** Compute the Pearson correlation.

Steps:

Q83: What is the covariance?

Q84: What is the standard deviation of the predictor variable?

Q85: What is the standard deviation of the criterion variable?

Q86: What is the Pearson’s r value?

Q87: What is the best interpretation of your Pearson correlation in Q6?

A. As ‘hours studied’ goes up there is a corresponding increase in ‘score on quiz’

B. As ‘hours studied’ goes up there is a corresponding decrease in ‘score on

quiz’

Q88: The strength of the above relationship is considered

A. weak

B. moderate

C. strong

Part B**Compute the regression equation.

Steps:

Q89: What is the numeric value for the slope?

Q90: What is the y-intercept?

12

Q91: What is the regression equation?

Q92: Predict the total number of points on the quiz for a person studying 4 hours.

Q93: A variable that is being predicted by another variable is called a(n)

A. predictor variable

B. criterion variable

C. independent variable

D. two of the above are correct

Q94: Which of the following correlations is stronger?

A. + 2.56

B. – 0.87

C. + 0.53

Q95: Computing correlations is appropriate when we have

A. measurement data

B. categorical data

C. ratio data

D. two of the above are correct

Q96: Two variables, X and Y, have a significant linear correlation. Under what conditions can

the direction of causality be determined just from knowing the correlation coefficient?

A. when the correlation is negative

B. when the correlation is positive

C. both a) and b) are correct

D. neither a) nor b) are correct

Q97: If you conducted a study where you could account for 49% of the variability for one

variable with another variable, which of the following correlation coefficients did you find?

A. .49

B. .2401

C. .7

D. none of the above are correct

13

The following 3 questions (Q98 to Q100) are based upon the scatterplots below:

A

B

C

Q98:

If you were to compute a correlation between the X and Y variables for each of the three sets

of data, which set of data would yield a correlation closest to zero?

Q99:

If you were to construct a regression equation using the X variable to predict the Y variable

for each of the three sets of data, for which set of data would the regression equation have the

largest, positive slope?

Q100:

If you were to construct a regression equation using the X variable to predict the Y

variable for each of the three sets of data, for which set of data would the regression

equation have the most negative slope?

Bonus Section – 2 points (5 Questions)

**There can be more than one correct answer to the following questions. I am

looking for your reasons as to why you think your answer is correct**

1)

What is the most interesting thing that you have learned so far in this course and why do

you think it is the most interesting?

2)

What is the least interesting thing that you have learned so far in this course and why do

you think it is the least interesting?

3)

What is the most difficult thing that you have learned so far in this course and why do

you think it is the most difficult?

4)

What is the least difficult (easiest) thing that you have learned so far in this course and

why do you think it is the least difficult?

5)

What is the biggest challenge for you taking this online course?

14

Student’s Name:

Midterm Exam:

Answers

Q1 D

Q2 B

Q3 A

Q4 A

Q5

Q6 A

Q7 D

Q8 C

Q9 B

Q10 A

Q11 A

Q12 B

Q13 A

Q14 Number of eggs laid by snakes

Q15 Type of snakes: Rattlesnakes and King Cobras

Q16 Discrete

Q17 Ratio

Q18 A

Q19

Q20

Q21

Q22

Q23

Q24

Q25

Q26

Q27

Q28

Q29

Q30

Q31

Q32

Q33

Q34

Q35

Q36

Q37

Q38

Q39

Q40

Q41

Q42

Q43

Q44

Q45

Q46

Q47

Q48

Q49

Q50

Q51

Q52

Q53

Q54

Q55

Q56

Q57

Q58

Q59

Q60

Q61

Q62

Q63

Q64

Q65

Q66

Q67

Q68

Q69

Q70

Q71

Q72

Q73

Q74

Q75

Q76

Q77

Q78

Q79

Q80

Q81

Q82

Q83

Q84

Q85

Q86

Q87

Q88

Q89

Q90

Q91

Q92

Q93

Q94

Q95

Q96

Q97

Q98

Q99

Q100