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GB513 Unit 2 Quiz Latest 2017 (A++++ Answer)
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Question 1 2 / 2 points

A standard normal distribution has the following characteristics:

1) The mean and the variance are both equal to 1

2) The mean and the variance are both equal to 0

3) The mean is equal to the variance

4) The mean is equal to 0 and the variance is equal to 1

5) The mean is equal to the standard deviation

Question 2 2 / 2 points

The total area underneath any normal curve is equal to:

1) the mean

2) one

3) the variance

4) the coefficient of variation

5) the standard deviation

Question 3 2 / 2 points

Kristen Ashford purchased the subscribers list for Wind Surfing magazine. She plans to survey a sample of the subscribers before using the list in her mail order business. She chooses the first 100 of the 5,000 names. Her sample is a:

1) simple random sample

2) stratified sample

3) systematic sample

4) convenience sample

5) cluster sample

Question 4 2 / 2 points

The area to the right of the mean in any normal distribution is equal to:

1) the mean

2) 1

3) the variance

4) 0.5

5) –0.5

Question 5 2 / 2 points

If x is a normal random variable with mean 80 and standard deviation 5, the z-score for x = 89 is:

1) 1.8

2) –1.8

3) 1.6

4) –1.6

5) 8.0

Question 6 2 / 2 points

Within a range of z scores from –1 to +1, you can expect to find _______ percent of the values in a normal distribution.

1) 95

2) 99

3) 68

4) 34

5) 100

Question 7 2 / 2 points

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 more than 1100 hours?

1) 0.4772

2) 0.9772

3) 0.0228

4) 0.5228

5) 0.5513

Question 8 2 / 2 points

Completion time (from start to finish) of a building remodeling project is normally distributed with a mean of 200 workdays and a standard deviation of 10 workdays. To be 99% sure that you will not be late in completing the project, you should request a completion time of _______ workdays.

1) 211

2) 207

3) 223

4) 200

5) 250

Question 9 2 / 2 points

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 746 AMEX 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:

1) disproportionate systematic sample

2) disproportionate stratified sample

3) proportionate stratified sample

4) proportionate systematic sample

5) proportionate cluster sampling

Question 10 2 / 2 points

Suppose 40% of a student population works part time. If a random sample size of 300 students is drawn from the population, then the probability that 44% or fewer of the samples work part time is:

1) 0.0793

2) 0.4207

3) 0.9207

4) 0.9900

5) 1.0000

 

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