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- 1) A recent study of breast cancer revealed t

1) A recent study of breast cancer revealed that 13% of the women in the sample used antibiotics more than 500 days in their lifetime. Further, 79% of these Åheavy antibiotics users developed breast cancer. According to the American Cancer Society, one in twelve women will develop breast cancer at some time in her life. Of the numbers mentioned, which are parameters?
A.
79% and 500 days
B.
13% and one in twelve
C.
13% and 79%
D.
79% and one in twelve
2) A survey was mailed to a total of 400 students; 100 were randomly selected from each of the freshman, sophomore, junior and senior classes last semester. What sampling method was used?
A.
Systematic sample
B.
Stratified sample
C.
Cluster sample
D.
Simple random sample
3) A statistician working for the Department of the Interior is constructing a systematic random sample of trees in a forest preserve. All trees have been identified and numbered with a non-invasive number attached to the bark. The statistician wishes to estimate the mean height of the trees in the forest preserve, and has calculated an appropriate sample size of n=43 trees. The 587th of the 731 trees in the preserve was selected as the first observation in the sample. What is the tree number of the second observation in the sample?
A.
604
B.
630
C.
588
D.
544
4) Which of the following is an example of statistical inference?
A.
Calculating the mean age of patients discharged from hospitals in New York State in 1997.
B.
Calculating the amount of fly spray needed for your orchard next season.
C.
Calculating the mean number of fruit trees damaged by Mediterranean fruit flies in California last year.
D.
Counting the number of patients who file malpractice suits after being discharged from hospitals in New York State.
5) Which of the following statements is not true?
A.
Estimating parameters is an important aspect of descriptive statistics.
B.
A statistical test may be significant yet have no practical importance.
C.
Statistics is the science of collecting, organizing, analyzing, interpreting, and presenting data.
D.
Scientific progress consists of continual refinement of theories through hypothesis testing.
6) Which of the following statements is false?
A.
The main goal of descriptive statistics is to estimate characteristics of populations.
B.
Statistical inference is the process of making a prediction based on only a small piece of information.
C.
A summary measure calculated from some of the items of interest is a statistic.
D.
A summary measure calculated from all items of interest is a parameter.
7)
Textbook Price Number of Textbooks
$25 to $35 2
35 to 45 16
45 to 55 5
55 to 65 7
65 to 75 20
Estimate the mean price of a textbook.
A.
$60.00
B.
$55.40
C.
$11.08
D.
$554.00
8) A supermarket has determined that daily demand for eggs has a bell-shaped distribution, with a mean of 55 cartons and a standard deviation of six cartons. If the supermarket begins each morning with a stock of 61 cartons of eggs, approximately what percentage of days will there be a surplus of eggs?
A.
Å68%
B.
Å84%
C.
Å18%
D.
Å16%
9) The average score for a class of 30 students was 75. The 20 male students in the class averaged 70. The 10 female students in the class averaged
A.
75
B.
70
C.
80
D.
85
10) The Information Commons in the main library has 150 personal computers. The probability that any one of them will require repair on a given day is 0.02. To find the probability that exactly 25 of the computers will require repair, one would use what type of probability distribution?
A.
Normal distribution
B.
Hypergeometric distribution
C.
Poisson distribution
D.
Binomial distribution
11) Which of the following is a characteristic of every binomial distribution?
A.
Each outcome is mutually exclusive.
B.
The outcome of a trial depends on the number of trials.
C.
The probability of success increases from trial to trial.
D.
Each outcome is dependent on the previous outcome.
12) Which of the following cannot generate a Poisson distribution?
A.
The number of defects in a new automobile
B.
The number of goals in the World Cup soccer game
C.
The number of customers arriving at an ATM in a minute
D.
The number of people at a movie theatre on Friday evening
13)
The Big Red Arcade and Pizza Palace caters to young teens and sells tokens to play arcade games for 25 each and slices of pizza for 50 each. The distribution of sales of pizza slices per customer and sales of arcade tokens per customer is below.
# Slices of Pizza 0 1 2 3 4 5
Probability 0.05 0.10 0.20 0.30 0.15 0.20
# Arcade Games 0 1 2 3 4 5
Probability 0.01 0.04 0.15 0.20 0.25 0.35
What is the total expected per customer revenue for pizza slice sales and arcade token sales?
A.
$2.42
B.
$1.34
C.
$2.60
D.
$6.69
14) Past history shows that 70% of college students prefer Pepsi. Groups of nine students are selected. Describe the histogram that would represent this distribution. The histogram would be:
A.
left-skewed with nine columns.
B.
right-skewed with ten columns.
C.
right-skewed with nine columns.
D.
left-skewed with ten columns.
15)
The Big Red Arcade and Pizza Palace caters to young teens and sells tokens to play arcade games for 25 each and slices of pizza for 50 each. The distribution of sales of pizza slices per customer and sales of arcade tokens per customer is below.
# Slices of Pizza 0 1 2 3 4 5
Probability 0.05 0.10 0.20 0.30 0.15 0.20
# Arcade Games 0 1 2 3 4 5
Probability 0.01 0.04 0.15 0.20 0.25 0.35
What is the probability that revenues from pizza slice sales will be greater than $1.00 per customer?
A.
.85
B.
.43
C.
.65
D.
.95
16) The expected value of the sampling distribution of the sample mean equals the population mean
A.
when the population size N > 30.
B.
for all populations.
C.
when the population is symmetric.
D.
when the population is normally distributed.
17) The standard error of the sample mean is equal to 5 when n=25. If the sample size increases by a factor of four, how will the standard error change?
A.
It will be cut to ¼ of 5
B.
It will quadruple
C.
It will be cut in half
D.
It will double
18) Which of the following statements is consistent with the Central Limit Theorem?
A.
When we know s, the variation in the sample means will be equal to that of the population.
B.
When µ and s are known, the population will be approximately normally distributed.
C.
If a population has µ and s, a sample from that population will be normally distributed if the sample size is large enough.
D.
Means of samples of n=30 from an exponential distribution will be approximately normally distributed.
19)
Construct a 95% confidence interval estimate for the difference between the means of two normally distributed populations, where the unknown population variances are assumed not to be equal. Summary statistics computed from two independent samples are as follows:
The upper confidence limit is:
A.
24.911.
B.
19.123.
C.
28.212.
D.
5.788.
20) Ceteris paribus, which is narrower, a 95% confidence interval with n=100 or a 99% confidence interval with n=30?
A.
They are the same width.
B.
The 95% confidence interval
C.
The 99% confidence interval
D.
Need the margin of error to tell
21)
A study of 200 insomniacs paid for by the Serta Mattress Company found that the average insomniac counted 350 sheep before falling asleep, with a standard deviation of 120. An insomniac is a person who has difficulty falling asleep. Some useful numbers might be:
=NORMSINV(0.89) 1.2265
=NORMSINV(0.945) 1.5982
=TINV(0.89,199) 0.1385
=TINV(0.11,199) 1.6053
=TINV(0.055,199) 1.9302
Out of the 200 insomniacs, 98 reported regularly watching The Late Show with David Letterman before they began to count sheep. Calculate the margin of error for a 78% confidence interval of the true proportion of insomniacs who regularly watch David Letterman before counting sheep.
A.
0.136
B.
0.043
C.
0.056
D.
0.164

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