### Question details

A market research firm is investigating the appeal of three
\$ 20.00

1. A market research firm is investigating the appeal of three package designs. The table below gives information obtained through a sample of 200 consumers. The three package designs are labeled A, B, and C. The consumers are classified according to age and package design preference.
A
B
C
Total
Under 25 years
22
34
40
96
25 or older
54
28
22
104
Total
76
62
62
200
If one of these consumers is randomly selected, what is the probability that the person prefers design A? (Points : 4)
0.76
0.38
0.33
0.22
0.39
2. Let A be the event that a student is enrolled in an accounting course, and let S be the event that a student is enrolled in a statistics course. It is known that 30% of all students are enrolled in an accounting course and 40% of all students are enrolled in statistics. Included in these numbers are 15% who are enrolled in both statistics and accounting. Find the probability that a student is in accounting and is also in statistics. (Points : 4)
0.15
0.70
0.55
0.12
0.60
3. If X and Y are mutually exclusive events, then if X occurs _______. (Points : 4)
Y must also occur
Y cannot occur
X and Y are independent
X and Y are complements
A and Y are collectively exhaustive
4. The area to the left of the mean in any normal distribution is equal to _______. (Points : 4)
the mean
1
the variance
0.5
-0.5
5. If x is a normal random variable with mean 80 and standard deviation 5, the z-score for x = 88 is ________. (Points : 4)
1.8
-1.8
1.6
-1.6
8.0
6. Within a range of z
scores from -1 to +1, you can expect to find _______ per cent of the values in a normal distribution. (Points : 4)
95
99
68
34
100
7. The expected (mean) life of a particular type of light bulb is 1,000 hours with a standard deviation of 50 hours. The life of this bulb is normally distributed. What is the probability that a randomly selected bulb would last fewer than 1100 hours? (Points : 4)
0.4772
0.9772
0.0228
0.5228
0.5513
8. Completion time (from start to finish) of a building remodeling project is normally distributed with a mean of 200 work-days and a standard deviation of 10 work-days. To be 99% sure that we will not be late in completing the project, we should request a completion time of _______ work-days. (Points : 4)
211
207
223
200
250
9. Financial analyst Larry Potts needs a sample of 100 securities listed on either the New York Stock Exchange (NYSE) or the American Stock Exchange (AMEX). According to the Wall Street Journal's "Stock Market Data Bank," 2,531 NYSE securities and AMEX 746 securities were traded on the previous business day. Larry directs his staff to randomly select 77 NYSE and 23 AMEX securities. His sample is a ____________. (Points : 4)
disproportionate systematic sample
disproportionate stratified sample
proportionate stratified sample
proportionate systematic sample
proportionate cluster sampling
10. Suppose 40% of a student population possess works part time. If a random sample of size 300 is drawn from the population, then the probability that 44% or fewer of the samples works part time is _______. (Points : 4)
0.0793
0.4207
0.9207
0.9900
1.0000

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