stats half
QUESTION 1
1. Data that are categorical but can be rank-ordered in a meaningful way are called:
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Nominal |
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Interval |
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Ordinal |
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Ratio |
3.5 points
QUESTION 2
1. The “standard normal distribution” table (i.e., the z-table) shows the relationship between two variables: the z-score and a probability (i.e., an area under the normal distribution).
True
False
3.5 points
QUESTION 3
1. Given a normally distributed variable (x), the formula: z = (x - µ) ÷ σ can be used to determine the value of x at a specific point on the x-axis, if you know the z-score.
True
False
3.5 points
QUESTION 4
1. A probability distribution is a theoretical but a frequency distribution is based on actual results/data.
True
False
3.5 points
QUESTION 5
1. Which of the following symbols represents the variance of the population?
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σ2 |
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σ |
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μ |
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s2 |
3.5 points
QUESTION 6
1. When calculating a binomial probability, the answer must be in the range of 0.00 to 1.00.
True
False
3.5 points
QUESTION 7
1. Which of the following is NOT an assumption for (property of) the binomial distribution?
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The trials are independent |
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Two outcomes are possible on each trial in the experiment |
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The experiment consists of n identical trials |
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The probabilities of success and failure at each trial must be equal |
3.5 points
QUESTION 8
1. A negative value of Z indicates:
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The number of standard deviations a measurement is to the right of the mean |
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The number of standard deviations a measurement is to the left of the mean |
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That a mistake has been made in computations, since Z cannot be negative |
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The area corresponding to the z-score is negative |
3.5 points
QUESTION 9
1. A variable with equal distances between points on a scale, which also has a true meaningful zero is:
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Ordinal |
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Cardinal |
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Ratio |
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Nominal |
3.5 points
QUESTION 10
1. A probability distribution showing the probability of x successes in n trials, where the probability of success does not change from trial to trial, is termed a:
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uniform probability distribution |
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binomial probability distribution |
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t distribution |
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normal probability distribution |
3.5 points
QUESTION 11
1. For which level(s) of measurement are arithmetic operations inappropriate?
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The ratio scale |
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The interval scale |
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Both the ratio and interval scales |
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The nominal scale |
3.5 points
QUESTION 12
1. In a binomial experiment:
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The probability does not change from trial to trial |
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The probability does change from trial to trial |
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The probability could change from trial to trial, depending on the situation under consideration |
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None of the above |
3.5 points
QUESTION 13
1. In constructing a frequency distribution, as the number of classes are decreased, the class width:
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Decreases |
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Remains unchanged |
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Increases |
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Can increase or decrease depending on the data values |
3.5 points
QUESTION 14
1. The measure of central tendency that is the point at which half the scores fall above and half the scores fall below is the:
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Mode |
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Range |
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Median |
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Mean |
3.5 points
QUESTION 15
1. In a sample of 800 students in a university, 240, or 30%, are Business majors. The 30% is an example of:
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A sample |
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A population |
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Statistical inference |
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Descriptive statistics |
3.5 points
QUESTION 16
1. Given a normally distributed variable (x), if you know that for a value of x = -27 the z-score = 0.67, what is the probability of any x value being below -27?
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0.9965 |
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0.7486 |
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-0.2514 |
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0.2514 |
3.5 points
QUESTION 17
1. Data which uses numerical values, has an equal distance between points on the scale, and does not have an absolute zero is:
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Nominal |
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Ordinal |
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Normal |
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Interval |
3.5 points
QUESTION 18
1. The primary method for controlling/minimizing sampling error is to:
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Increase sampling bias |
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Take multiple samples |
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Select samples from a heterogeneous population |
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Increase sample size |
3.5 points
QUESTION 19
1. A numerical value used as a summary measure for a sample, such as sample mean, is known as a:
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Population parameter |
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Sample parameter |
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Sample statistic |
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Population mean |
3.5 points
QUESTION 20
1. The summaries of data, which may be tabular, graphical, or numerical, are referred to as:
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Inferential statistics |
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Descriptive statistics |
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Statistical inference |
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Report generation |
3.5 points
QUESTION 21
1. The Quickie Sales Corporation has just been given a sales estimate for the upcoming quarter. The estimate indicates that sales (in millions of dollars) will be normally distributed with µ = 325 and σ = 60. Assuming this estimate is accurate, what is the probability that Quickie will have quarterly sales in excess of $350 million?
QUESTION 22
The U.S. Postal Service handles seven basic types of letters and cards: third class, second class, first class, air mail, special delivery, registered and certified. The mail volume during 1977 is given in the table below. What was the average revenue per ounce for these services during the year?
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Type of Mailing |
Ounces Delivered (in millions) |
Price per Ounce |
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Third class |
16,400 |
$0.05 |
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Second class |
24,100 |
0.08 |
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First class |
77,600 |
0.13 |
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Air Mail |
1,900 |
0.17 |
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Special delivery |
1,300 |
0.35 |
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Registered |
750 |
0.40 |
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Certified |
800 |
0.45 |
QUESTION 23
1. Here are the ages of 30 people who bought CD players at Symphony Music Shop last week: 26, 37, 40, 18, 15, 45, 32, 68, 31, 37, 20, 32, 15, 27, 46, 44, 62, 58, 30, 42, 22, 26, 44, 41, 34, 55, 50, 63, 29, 22. Construct a frequency distribution (table) with 6 classes to summarize these data.