Download For problems 1-3, choose the appropriate level of measurement. 1

For problems 1-3, choose the appropriate level of measurement.
1) The number of new cases of AIDS reported in the United States during a one-yr period.
a) Ordinal b) nominal c) discrete d) continuous
2) Cholesterol levels
a) Ordinal b) nominal
c) discrete
d) continuous
3) Injuries classified according to their level of severity: fatal injury, severe, moderate, minor
a) Ordinal b) nominal c) discrete d) continuous
4) A sample of 1000 students at a college were randomly selected and asked if they owned a computer. Eight hundred said yes. “Estimate” the
probability that a student does not own a computer.
5) If a die is rolled three times, find the probability of rolling a 5 EXACTLY 2 times out of the 3 rolls?
Identify the following value as a statistic or a parameter, and briefly explain your answer.
6) When considering only patients in hospital A. All patients at hospital A were asked to fill out a survey last year. The percentage of outpatients
who didn’t have insurance was 20%.
Is this an example of a statistic or a parameter? a) Statistic
b) Parameter
7. The college astronomy club has been counting meteoroid each night for the past week. Between the hours of 10pm and 1am, the meteoroid
for each night was
15 12 15 10 17 18 15
Compute the (a) mean, (b) median, (c) mode, for the meteoroid counts on the past seven nights.
8. The following are statistics exam scores:
40 46 55 57 58 60 64 65 72 72 73 75 75 77
78 80 82 84 87 88 89 90 90 92 95 99 99
(a) Construct a frequency Table, with 6 classes.
(b) From (a) make a Histogram using class boundaries (6 classes):
(c) from part (b) (after proper normalization) : what is the probability of getting an exam score between 80 and 89?
9. Displayed below is a frequency distribution containing a summary of the resting systolic blood pressures for a sample of 30 patients with
ischemic heart disease. Compute the grouped mean.
Blood Pressure
Number
(mm Hg)
Patients
________________________________
115-124
4
125-134
5
135-144
5
145-154
7
155-164
5
165-174
4
10. Find (a) the mean and (b) standard deviation of the following data:
3,7, 9, 8, 20 , show all formulas and work
11. What does a z score measure? Explain clearly.
12. Which is relatively better, a score of 75 on a history test or a score of 27 on a psychology test? Scores on the history test have a mean of 80
and a standard deviation of 12. Scores on the psychology test have a mean of 30 and a standard deviation of 8. Explain clearly.
13. Let the random variable x represent the number of Heads among 4 coin flips. (a) Find the probability of getting LESS THEN two heads (a)
Find the mean and standard deviation (hand calculate or use calculator)Hint: write the sample space of the possible outcomes.
14. What is the best measure of central tendency for the following data and why?
Test scores: 23 72 75 79 80 83 84 84 87 88 90 92 92 (don’t calculate)
15. Explain the relationship between a random variable x , the random variable’s probability distribution
what would the answer be to
p ( x ) , and thus explain (in words)
P(a  x  b) =?
16. Consider the data set 20 23 72 75 79 80 83 84 84 87 88 90 92 92. (a) Find the five number summary. (b) Draw the box-plot for
the 5 number summary in part (a)
17. Suppose that the average wait time in a bank line is 3 minutes with a standard deviation of 1.25 minutes. Last Friday I waited for 8 minutes
before getting a teller. (a) Find the Z-score for my wait time (b) Would this be considered unusually long? Explain.