Math 114 - Spring 2008
Homework up to Exam 1
Due:
01/30/08
(1)
Fill out the information sheet.
(2) Read Section 1.1 and go over your class notes.
(3) Complete the pre-assessment on your own without looking at
notes, books, etc.
(4) Using the interruption time data for Old Faithful given
below:
a) Create a histogram (choose the intervals
as you please).
b) Create a pie chart.
c) Write a couple of sentences about your
observations from the data/charts.
Interruption time data for Old Faithful (in minutes):
78 74 68 76 80 84 50 93 55 76 58 74 75 80 56 80 69 57 90 42 91 51 79 53
82 51
76 82 84 53 86 51 85 45 88 51 80 49 82 75 73 67 68 86 72 75 75 66
84 70 79 60
86 71 67 81 76 83 76 55 73 56 83 57 71 72 77 55 75 73 70 83
02/01/08 (1) At
the end of Section 1.1 starting on page
9, hand in #2, 7 (add part (d) Is
this data sensible?), 9, 10,
17, 22.
(2) Read Stephen Jay Gould's article "The Median Isn't the
Message," and
summarize the statistical
issues in applying the concept of the median
in the real world that gave the
author reason to hope. Write two or three
paragraphs, and be sure to use correct grammar and spelling.
(3) Study for a short quiz.
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02/04/08 (1) Log on
to WileyPLUS and by 1 pm Monday do
assignment: Sec 1.1 - Practice.
(2) If you haven't already taken the Level 1 math placement exam, take
it in
Serra 205, preferably between 8am and noon on Monday. Practice
problems
are available at the web site: http://mathplacement.sandiego.edu
(3) Finish the worksheet started in class.
(4) Start reading the
hand out on normal distributions.
02/06/08 (1) By 1 pm,
do web assignment: Sec 1.1.
(2) Problem 1.
Blood phosphates. The levels of various substances in the blood
influence a person's health. The following are measurements of
the level of
phosphate in the blood of a patient, in milligrams of phosphate per
deciliter of
blood, made on 6 consecutive visits to a clinic:
5.6 5.2 4.6
4.9 5.7 6.4
(a) Compute by hand the mean of the six observations.
(b) Use the definition of standard deviation to compute by hand (show
your work
neatly) the standard deviation of the six observations.
(c) Now enter the data into your calculator, and use the calculator to
find the
mean and the standard deviation.
(d) What value would correspond to a z-score of 2.1?
What value would correspond to a z-score of -0.4?
(3) Problem 2.
Choose four numbers from the whole numbers 0 through 10, with
repeats allowed, such that:
(a) the four numbers have the smallest possible standard deviation.
(b) the four numbers have the largest possible standard deviation.
(c) Is there more than one correct answer possible in either (a) or (b)?
(4) Continue reading the handout on normal distributions.
02/08/08 (1) Read Sec
1.2, and go over your class notes.
(2) Study for a short quiz.
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02/11/08 (1) Read Sec
1.3.
(2) By 1 pm, do the WileyPLUS assignment, Sec 1.2 - part 1.
(3) Written homework to be handed in:
Problem 1. The
distribution of heights of women aged 20 to 29 is approximately normal
with mean 64 inches and standard deviation 2.7 inches. Use the
68-95-99.7 rule to answer the following questions.
(a) Between what heights do the middle 95% of women
aged 20 to 29 fall?
(b) What percent of these women are taller than 61.3
inches?
Problem 2. Using
the information from problem 1 and the fact that the distribution of
heights of men in the same age range is approximately normal with mean
69.3 inches and standard deviation 2.8 inches, what percent of young
men are shorter than the mean height of young women?
Problem 3. The
army reports that the distribution of head circumferences among male
soldiers is approximately normal with mean 22.8 inches and standard
deviation 1.1 inches.
(a) What can be said about the head circumferences of
the 20% of the soldiers who need the largest hats?
(b) What percent of soldiers have head circumference
between 21.7 inches and 23.9 inches?
Problem 4. Ty
Cobb’s batting average was .420 in 1911; Ted Williams’ was .406 in
1941; and George Brett’s was .390 in 1980. These batting averages
cannot be compared directly because the distribution of major league
batting averages has changed through the years. The distributions
are quite symmetric and (except for outliers such as Cobb, Williams and
Brett) reasonably normal. Here is the information:
Decade Mean Standard Deviation
1910s .266 .0371
1940s .267 .0326
1970s .261 .0317
Notice that the mean has stayed roughly constant but the standard
deviation has dropped. Compute the z-scores for the batting
averages for Cobb, Williams and Brett and write (in whole sentences) a
brief comparison of how far each stood above his peers.
Problem 5. The
yearly snowfall totals in inches for Buffalo, New York, during the
years 1910-1949 are:
126, 82, 78, 51, 91, 76, 105, 87, 110, 25, 69, 54, 40, 64, 47, 73, 80,
84, 81, 60, 79, 74, 50, 55, 72, 49, 104, 52, 82, 84, 78, 79, 90, 86,
58, 121, 111, 65, 40, 40.
(a) Make a histogram of the above data. Does the data look
normally distributed? Why or why not?
(b) Calculate the mean and standard deviation of snowfall totals.
(c) How close does the data come to meeting the 68-95-99.7 rule of an
ideal normal distribution?
2/13/08
(1) Read Sec 1.3 and 1.4.
(2) Do WileyPLUS assignment, Sec 1.2 - part 2, by 1 pm. It is
possible that you will be asked for your WileyPLUS registration number
(which came packaged with the textbook). Our two weeks of free
use are over.
(3) Written homework to be handed in:
Section 1.2 #2, 12, 13 and the
problem below.
Problem on two-variable data:
The maximum temperatures in degrees Fahrenheit at Lindbergh Field, San
Diego, on January 1 of various years:
Year Temp
2004
64.0 (a)
Make a scatter plot of this data.
2000
59.0 (b)
What, if anything, does this say about global warming?
1996 72.9
1992 66.9
1988 63.0
1984 73.0
1980 70.0
1976 60.1
2/15/08
(1) Read Sec 1.5.
(2) Do WileyPLUS assignment, Sec 1.2-1.4, by 1 pm.
(3) Written homework to be handed in:
Section 1.3 #4, 6, 8, 10
Section 1.4 #10, 11, 12
(4) Study for a short quiz.
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2/18/08
(1) Read Sec 2.1 - 2.3.
(2) Do web assignment, Sec 1.3-1.5, by 1 pm.
(3) Written homework to be handed in:
Section 1.4 #4
Section 1.5 #6, 8, 10, 11, 16
2/20/08
(1) Read Sec 2.4 - 2.6.
(2) Do web assignment, Sec 2.1-2.3, by 1 pm.
(3) Written homework to be handed in:
Section 2.1 #6, 8, 9
Section 2.2 #6, 10
Section 2.3 #16
2/22/08
(1) Read Sec 2.6 - 2.8.
(2) Do web assignment, Sec 2.4-2.7, by 1 pm.
(3) Written homework to be handed in:
Section 2.3 #18, 19
Section 2.4 #6, 8, 10
(Hint on #10: scales)
Section 2.5 #6
Section 2.6 #4
(4) Study for a short quiz.
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2/25/08
(1) Read Sec 3.1 + 3.2. (We will return to Sec 2.9 later.)
(2) Do web assignment, Sec 2.5-2.7, by 1 pm.
2/27/08
(1)
Do web assignment, Sec 2.6-2.8, by 1 pm.
(2) Written homework to be handed in:
Section 2.6 #13
Section 2.7 #14, 16, 18, 19
Section 2.8 #6, 12, 14, 16,
24, 28
2/29/08
(1) Re-read Sec 3.1 + 3.2.
(2) Do web assignment, Sec 2.8+3.1, by 1 pm.
(3) Study for a short quiz.
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3/3/08
(1) Read Sec 2.9.
(2) Do web assignment, Sec 3.1+3.2, by 1 pm.
(3) Written homework to be handed in:
Page 135 #3, 14
Section 3.1 #5, 6, 8
Section 3.2 #6,
10abfi, 11
3/5/08
(1) Do web assignment, Sec 3.2, by 1 pm.
(2) Written homework to be handed in:
Section 3.2 #32
Page 205 #7, 10
(3) Be sure to bring your calculator to class.
3/7/08
(1) Do web assignment, Sec 2.9, by 1
pm.
(2) Written assignment to be handed in:
Redo page 205 #10.
Problem on the back of
the handout on correlation coefficients.
(3) No quiz this week; we will review in class.
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3/10/08
Exam 1 on Chapter 1,
Chapter 2, Sections 3.1and 3.2, and handouts on statistics.