Practice Exam (or Quiz) Problems
Dr. Jinwook Lee
Problem 1. Suppose that 5 percent of men and 0.25 percent of women are color-blind. A color-blind person
is chosen at random. What is the probability of this person being male? Assume that there are an equa
Decision Sciences
LeBow College of Business
Drexel University
3220 Market Street
Philadelphia, PA 19104
STAT 202 Business Statistics II
Name (Last, First) :
Midterm (Version A)
Student ID Card# :
Part I. T/F Questions (20 points total, 1
\ uruuauun stun a;
{The following infermatlon applies to the questions displayed below}
Conslder me followlng data on 20 chemlcal reactlons. wlm Y= chromatographlc retentlon tlme {seconds} and
X= molecular welght lgmlrn ole}.
Retentlon Tlrne and Molecular
Score: 81.081310 Points 26.15 96
< Question 2 {of 31} v >
Award: 0 out mono points 5'10" WW'
A certain model of remotecontrol garage door opener has twelve binary (oﬁfon) switches. The homeowner
can set any code sequence.
(a) How many separate codes can b
Score: 81.08810 Points 26.15 95
< Question 12(o1'31} v >
1 2 . Award: 6.67 out mono points
Times fora surgical procedure are normally distributed. There are two methods. Method A has a mean of
26 minutes and a standard deviation of 4 minutes, while method
Score: 81.081310 Points
Award: 5 out (#1000 points
26.15 95
(
Question 9 [of 31]
Showmyanswar
The probability that a bakery customer will ordera birthday cake is 0.08.
[all What is the expected number of customers until the first birthday cake is ordere
Score: 81.081810 Points
11.
Award: 0 out M1090 points
If the weight (in grams) of cereal in a box of Luc ky Charms is N(482,?), what is the pmbability that the box
will contain less than the advertised weight at 456 gm? Note: You may need to use Excel to
(c) What are the quartiles? {Round your answers to 2 decimal plaoele
13" Quartile 14.501 0.01‘ inches persecond
3rd Quartile 35. 50 t 0. 01‘ inches per second
(d) What percentage of subway riders must reswipe the card because they were outside the
Award: 334- out M1090 points
In Northern Yellowstone Lake, earthquakes occur at a mean rate of 1.5 quakes per year. Let X be the
number of quakes in a given year.
(a) Justify the use of the Poisson model.
Earthquakes are random and irkieperkient events.
[
Award: 0 out mono points 5'10“ W WT
Software filters rely heavily on “blacklists“ (lists of known “phishing‘ URLs) to detect fraudulent emails. But
such filters typically catch only 29 percent of phishing URLs. Jason receives 26 phishing emails.
[all What
[bl What is the probability that one of the next eight c ustomers who order beer will order light beer? {Round
your answer to 4 decimal plaoes.}
.0548 1.0001
Probability
[cl What is the probability that two of the next eight c ustomers who order b
Score: 81.081310 Paints 26.15 95
< Quasﬁon 5ror31} v >
5 . Award: 10 out of 10.00 polnts
ﬁrs a blrthday gm. you are rnaIlIng a new personal dlgltal asslsrant IPDﬁI] to your cousln In Toledo. The FDA
cost $209. There Is a 4 percent chance It wlll be lost o
[of Cal: ulate the following probabilities: {Round your answers to 4 decimal places.}
if. F’(L} ml
iii.P(H| C} ml
mile, E
v. PH. and 8) MI
vi. F’(L and C} MI
[bit Do you see evidence that noise level depends on flight phase?
Yes
Explanation:
in:
i. P(B)
v. F’(S and W} 0. 2550 1 0.0001
vi. F’W'and B} 02150 i 0. 000‘!
[by Do you see evidence that smoking and race are not independent?
Yes
[d1 1il'lI'hy might public health officials be interested in this type of data?
The health officials might target or des
M&Ms are blended in a ratio of 9 percent brown, 13 percent yellow, 10 percent red, 20 percent blue, 1?
percent orange, and 3-1 percent green. Suppose you choose a sample of two M&Ms at random from a bag.
[a) How many elements are there in the sample space
{b} What is the probability that the dealership will wait at least a year? [Round your answer to 4 decimal
places}
P I | 1in 0. 2369 t 0. 0001
(3.} What is the probability that the dealership will wait at least 2 year? [Round your answer to 4 decimal
plac
in. .u.-.m.:, "um“.“w. ”ﬂu". H. m. .f._.u .,._,._. "mu”?
The sodlum content of a popular sports dnnk Is Ilsted as 200 mg In a 3202 bottle. Analysls 0f20 bottles
Indlcates a sample mean of 211.5 mg wlth a sample standard devlatlon 0f18_5 mg.
15_ Award: u o
Homework 4
Score: 27.71f100 Polms 27.71 96
< Question 8 {019} V >
[The mrrowmgmformamn apprres to me quesrlons o'rspfayeo‘ below}
Conslder me followlng prlces and accuracy rallngs for 2? stereo speakers.
Prlce and Aocuracy of Selected Stereo Speaker
th elr goal. uslng a = .025?
2 8 _ Award: 10 out of 10.00 points
(a) Hg: 17 S .95 pages versus H1: 17 a .95. Choose the rlght optlon.
a . Reject HOW zcalc >186
O Reject Hoii zcalc <1.96
2 9_ Award: 0 out mono points 5'10" W m'
lb) Calculate the Test stati
l—l
3 0_ Award: 0 out mono points 5'10" Wm'
[c-1) The null hypothesis should be rejected.
No
[c-Z) The true proportion is greater than .95.
No evidence to support
[03) The company is exceeding its goal.
No evidence to support
Explanation:
The test statist
(8-3] The null hypothesls should be rejected.
0 True
0 . False
2 5 _ Award: 10 out M1000 point5
(8-4] The true proponlon I5 greater than .50.
2 6 _ Award: 0 out M1090 points Show W WT
[b—1) Find the p—V8Iue. [Round your answer to 4 decimal places.}
p—vdue
Score: 81.08/310 Points 26.15 '56
< Questions 19 -21 {0131} v >
{The following rnfonttatton applies to the questions displayed below}
At Ajax Sprlng Water, a half-Ilter bottle of soﬁ dnnk Is supposed to contaln a mean of 538 ml. The ﬂlllng
process follows
Score: 81.081810 Points 26.15 96
14.
< Quesﬁon14{of31} v >
Award: 0 out enono points 5'10“ W m'
A random sample of 30 lunch orders at Noodles and Company showed a mean bill of $10.36 with a
standard deviation of $5.31. Find the 95 percent confidence inter
Award: 0 out of 10.00 points 5'10" "1? answer
[ct At the 5 percent level of significance (0 = 0.05) does the sample contradict the manufacturer‘s claim?
Reject Hg. The sample contradict the manufacturer’s claim.
Explanation:
Decision Rule: Reject Hg if lc
Simple regression was employed to establish the effects of childhood exposure to lead. The effective
sample size was about 122 subjects. The independent variable was the level of dentin lead (parts per
million). Below are regressions using various depende
Mark:
PV for 450,000 for 5 years
$1,796,719.52
PV for 100,000 for every year withdrawn
$
1,250,000.00
Total PV =
$3,046,719.52
So Mark would need $3,046,719.52 today for his dream retirement
Mike:
PV for $50,000 for 5 years
$199,635.50
PV for $750,000 for