MAT 121 Midterm: MAT121-2010Spring
Name:_________________________
MAT 121 Final Exam May 10, 2010 Version 1 Page 1
There are 10 questions. Do all parts of all questions. Show the work you do
to obtain an answer. A calculator and your textbook are allowed. No other books
or notes are allowed. Make sure you have seen and understand the material in
the syllabus about what sort of notes you are allowed to put in your book. Do not
share calculators.
Put your name on your blue book. Put all the work you wish to have graded
in your blue book. Turn in both your exam and your blue book together. When
you turn in your exam make sure your name gets checked off the list as having
turned in the exam.
1. (8 points) In each case tell whether the information given is at the nominal,
ordinal, interval, or ratio level of measurement. The number or word in
parentheses indicates what data you are to classify.
(a) The high temperature today was 100 degrees Fahrenheit. (100)
(b) That team placed 5th best in the league. (5th)
2. (8 points) In each case tell whether the sample is being selected by random,
systematic, cluster, stratified, or convenience sampling.
(a) A college wishes to survey a sample of its freshmen. It puts all their
names on individual slips of paper, puts them all in a box, mixes it up thoroughly,
then someone with eyes closed picks 50 of the slips of paper.
(b) A college wants to survey a sample of its freshmen. It puts all their
names in alphabetical order, then chooses every 10th name.
3. (8 points) Make a Pareto Chart for the following data.
Flavor of Ice Cream Number of Cones Sold
Chocolate 30
Vanilla 45
Coffee 10
Strawberry 20
4. (10 points) In a shipment of 100 apples 70 are rotten, 40 are wormy, and 20
are both rotten and wormy. If one apple is chosen at random, what is the
probability that it is either rotten or wormy?
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MAT 121 Final Exam May 10, 2010 Version 1 Page 2
5. (10 points) You want to make a confidence Interval for the proportion of people
in a certain state who support the death penalty. You want the confidence level to
be 95% and the error to be at most 0.02. Previous studies suggest the proportion
is near 0.57. How large should your sample size be?
6. (10 points) In a certain high school 70% of the students like mathematics.
Suppose 12 of them are selected at random with replacement.
(a) What is the probability that exactly 10 of them like mathematics?
(b) What is the probability that at least 10 of them like mathematics?
7. (12 points) Find the mean, median, mode, and midrange for the following list of
data.
5 5 5 6 8 9 9 11 13 15
8. (12 points) Consider the following list of data.
2 6 7 9 10 13 15 17 18 19 22 25
(a) Find the percentile of the data value 18.
(b) Find the value of the 20th percentile P20.
9. (12 points) The weights of cookies produced by a certain machine have a
mean of 0.72 ounces with a standard deviation of 0.14 ounces. If a simple
random sample of 50 of those cookies is taken, what is the probability that the
mean weight of that sample is greater than 0.73 ounces?
10. (10 points) A simple random sample of 60 students from a certain university
has a mean GPA of 3.16 with a sample standard deviation of 0.37. Construct a
90% confidence interval for the mean GPA of all students from that university.
Name:_________________________
MAT 121 Final Exam May 10, 2010 Version 2 Page 1
There are 10 questions. Do all parts of all questions. Show the work you do
to obtain an answer. A calculator and your textbook are allowed. No other books
or notes are allowed. Make sure you have seen and understand the material in
the syllabus about what sort of notes you are allowed to put in your book. Do not
share calculators.
Put your name on your blue book. Put all the work you wish to have graded
in your blue book. Turn in both your exam and your blue book together. When
you turn in your exam make sure your name gets checked off the list as having
turned in the exam.
1. (8 points) In each case tell whether the information given is at the nominal,
ordinal, interval, or ratio level of measurement. The number or word in
parentheses indicates what data you are to classify.
(a) The official color of SU is orange. (orange)
(b) The tuition at SU is $23,424. (23,424)
2. (8 points) In each case tell whether the sample is being selected by random,
systematic, cluster, stratified, or convenience sampling.
(i) You want to predict the outcome of a university wide election, so you ask
everyone you meet on your dorm floor this evening whom they intend to vote for.
(ii) A store asks a pollster to ask every 15th customer leaving the store
whether they thought the sales people in the store were polite
3. (8 points) Make a Pareto Chart for the following data.
Flavor of Ice Cream Number of Cones Sold
Chocolate 40
Vanilla 20
Coffee 50
Strawberry 15
4. (10 points) In a shipment of 100 apples 40 are rotten, 60 are wormy, and 30
are both rotten and wormy. If one apple is chosen at random, what is the
probability that it is either rotten or wormy?
Go to next page
Document Summary
Put all the work you wish to have graded (a) the high temperature today was 100 degrees fahrenheit. (100) (b) that team placed 5th best in the league. (5th) Mat 121 final exam may 10, 2010 version 1 page 1. Flavor of ice cream: (10 points) in a shipment of 100 apples 70 are rotten, 40 are wormy, and 20 are both rotten and wormy. Go to next page (a) a college wishes to survey a sample of its freshmen. It puts all their (b) a college wants to survey a sample of its freshmen. Mat 121 final exam may 10, 2010 version 1 page 2: (10 points) you want to make a confidence interval for the proportion of people in a certain state who support the death penalty. You want the confidence level to be 95% and the error to be at most 0. 02. Previous studies suggest the proportion is near 0. 57.
