STAT 200 Midterm Exam Fall 2019
I have completed this assignment myself, working independently and not consulting
anyone except the instructor.
NAME: Don J Hernandez
INSTRUCTIONS
• The exam is worth 100 points total.
• The quiz covers Weeks 1-5 materials.
• Make sure your answers are as complete as possible and show your
work/argument. When there are calculations involved, you should show how you
come up with your
answers with critical work and/or necessary tables. You must show why you choose
certain answer for true-or-false and multiple choice questions. Answers that come
straight from program software packages will not be accepted.
• The exam is open book and open notes. This means that you may refer to your textbook,
notes, and online course materials, but you must work independently and may not
consult
anyone. The brief honor statement is on top of the exam. If you fail to put your name under
the statement, your exam will not be accepted. You may take as much time as you wish,
provided you turn in your exam via LEO by the required deadline.
1. (5 points) True or False. Justify your answers for full credit.
(a) If the variance from a data set is zero, then all observations must be zero in this data set.
FALSE. If all data points (observations) are equal to the mean, then the standard deviation is 0.
(b) The variance of a data set cannot be negative, but the standard deviation can be negative.
FALSE. Standard deviation is a square root of variance which cannot be negative
(c) Suppose the minimum for a data set is 0.12. A careless assistant records it as 1.2, which is
the only mistake in the record keeping. The mistake will increase the mean as well as the
median of the data set.
FALSE. The mistake will increase the mean but not the median. The median is the middle value
of a data set, which divides the data set into two. The median is not affected by an outlier. An
extreme value can pull up or pull down the mean.
(d) The following distribution has a positive skew.
Page 1 of 10
, TRUE. Right skew is a positive skew.
(e) Interquartile range can measure central tendency.
FALSE. Interquartile range is a measure of variability.
2. (5 points) Choose the correct answer. Justify your answers for full credit.
(a) An agency conducts a survey on the choice of vegetable by Americans. It is reported by
the agency that 57% of the respondents prefers broccoli. The value 57% is
a. a parameter,
b. a statistic, this is sample survey and not a full population.
c. neither of the above.
(b) The volume of water in a glass is 12 oz. The value of 12 is from
a. a continuous data set, because it arises from measuring.
b. a discrete data set,
c. neither of the above.
(c) Which of the following is a qualitative variable?
a. Weight in kilograms
b. Number of days without precipitation
c. Ethnicity (words describing charateristic of the indivdual)
d. Average daily temperature
(d) For the following stem and leaf plot, how many numbers are there between 3 and 4? Please
note the numbers in the stem are in ones.
4|33
3|56
2|00456
Page 2 of 10
I have completed this assignment myself, working independently and not consulting
anyone except the instructor.
NAME: Don J Hernandez
INSTRUCTIONS
• The exam is worth 100 points total.
• The quiz covers Weeks 1-5 materials.
• Make sure your answers are as complete as possible and show your
work/argument. When there are calculations involved, you should show how you
come up with your
answers with critical work and/or necessary tables. You must show why you choose
certain answer for true-or-false and multiple choice questions. Answers that come
straight from program software packages will not be accepted.
• The exam is open book and open notes. This means that you may refer to your textbook,
notes, and online course materials, but you must work independently and may not
consult
anyone. The brief honor statement is on top of the exam. If you fail to put your name under
the statement, your exam will not be accepted. You may take as much time as you wish,
provided you turn in your exam via LEO by the required deadline.
1. (5 points) True or False. Justify your answers for full credit.
(a) If the variance from a data set is zero, then all observations must be zero in this data set.
FALSE. If all data points (observations) are equal to the mean, then the standard deviation is 0.
(b) The variance of a data set cannot be negative, but the standard deviation can be negative.
FALSE. Standard deviation is a square root of variance which cannot be negative
(c) Suppose the minimum for a data set is 0.12. A careless assistant records it as 1.2, which is
the only mistake in the record keeping. The mistake will increase the mean as well as the
median of the data set.
FALSE. The mistake will increase the mean but not the median. The median is the middle value
of a data set, which divides the data set into two. The median is not affected by an outlier. An
extreme value can pull up or pull down the mean.
(d) The following distribution has a positive skew.
Page 1 of 10
, TRUE. Right skew is a positive skew.
(e) Interquartile range can measure central tendency.
FALSE. Interquartile range is a measure of variability.
2. (5 points) Choose the correct answer. Justify your answers for full credit.
(a) An agency conducts a survey on the choice of vegetable by Americans. It is reported by
the agency that 57% of the respondents prefers broccoli. The value 57% is
a. a parameter,
b. a statistic, this is sample survey and not a full population.
c. neither of the above.
(b) The volume of water in a glass is 12 oz. The value of 12 is from
a. a continuous data set, because it arises from measuring.
b. a discrete data set,
c. neither of the above.
(c) Which of the following is a qualitative variable?
a. Weight in kilograms
b. Number of days without precipitation
c. Ethnicity (words describing charateristic of the indivdual)
d. Average daily temperature
(d) For the following stem and leaf plot, how many numbers are there between 3 and 4? Please
note the numbers in the stem are in ones.
4|33
3|56
2|00456
Page 2 of 10
