# ex1review _08-34_

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```					                Math 160 Fall 2009
Exam 1 Review
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This is just a guide to help you study. I do not guarantee that anything will or will not
be on the exam based on this guild.

1     Basics
Friday, September 18, 2009 in class. No books or notes. You may use a calculator.

§10.1-10.4, 10.6, 13.1-13.6, 14.1-14.2, average, median

2     Vocabulary
simple interest         annual percentage rate (APR)     compounding                  common ratio
geometric sequence      annual percentage yield (APY)    periodic interest rate       survey (poll)
sample                  target population                sampling frame               statistic
parameter               sampling error                   chance error                 sample bias
sampling proportion     simple random sampling           startiﬁed sampling           N -value
clinical study          capture-recapture method         association                  causation
confounding variables   controlled placebo study         placebo                      data
blind study             randomized control study         double-blind study           pie chart
data points             frequency table                  class intervals              bar graph
outliers                relative frequency               numerical variable           average
discrete variable       continuous variable              categorical variable         median

3     Formulae on Exam
The following formulae will be available to you during the exam:
￿     ￿                                         ￿            ￿
r nt                                            q T −1
F = P (1 + r)t         F =P 1+ n              F = P ert           P = Fq        q−1
￿ N ￿
c −1
F = P (1 + rt)        P + cP + c2 P + · · · + cN −1 P = P     c−1

4     Practice Exam
1. Deﬁne each of the following terms completely.
(a) quota sampling

(b) target population

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(c) parameter

(d) chance error

The next three problems are short answer problems. Carefully explain and
justify your answers in a few complete sentences.

2. With the Capture-Recapture method, sometimes the tagged individuals become more
likely to be prey to predators. If we know this was the case, should we assume our
estimate of N is an overestimate or an underestimate? Why?

3. Which is a better investment, a CD returning 5.25% APR compounded monthly or a
CD returning 5.375% APR compounded quarterly? (Hint: compute the APY of both
options.)

4. Geico claims they can “save you up to 15% on car insurance” by switching to their
company. You currently pay \$620 a year for car insurance through another company.
Geico quotes you \$540 a year for car insurance. Is their claim reasonable? Why or
why not?

For the rest of the problems, make sure you show all your work.

5. Alice, Bob, and Eve are running for class president of a class with 4207 students. A
telephone poll was taken the day before the election consisting of 250 randomly chosen
students. Of those 250 students, 80 said they were planning to vote for Alice, 65 were
planning to vote for Bob, and 105 were planning to vote for Eve.
(a) What is the sampling proportion?
(b) What is the target population?
(c) What is the statistic for votes for Alice?

6. A geometric sequence has initial term G0 = 3 and common ratio c = 0.7. What is G5 ?
What is GN ? What is the sum of the ﬁrst 14 terms of this sequence?

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7. Find the average and median for the following data {4, 7, 2, 11, 4, 6, 3, 4, 4, 6, 8, 2, 4, 5, 2}.

8. Given the bar graph below which represents relative frequencies of a test score, what
is the average score? What are the class intervals on this bar graph?

9. List an example of a discrete variable and also a continuous variable (do not use one
we discussed in class). Explain why the variable you chose is discrete or continuous.

10. You own a coﬀee shop and you have 180 boxes of ground coﬀee in storage which you
want to sell. 55 are from company A, 20 are from company B, 70 are from company
C, and 35 are from company D. You want to test the coﬀee to make sure it is all good.
You are willing to check 15 boxes to determine if the products are good. How would
you implement a stratiﬁed sampling method to test the coﬀee?

3

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