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