Part A: Answer the following questions (1-10)
1. What are the measures of central tendency?
2. What are the characteristics of mean, median, and mode?
3. What is the sampling error?
4. Name 6 reasons why we use samples instead of an entire population.
5. Name measures of spread or variability.
6. Explain the concept of error and uncertainty as it relates to decision making.
7. As discussed in the class live, what are 3 ways of calculating R2?
8. Suppose the classes for an organized set of data are as follows: please fill in the A column and answer the B question.
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Class
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A.
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B.
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Mid-Point
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What is the value of class width?
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0.235 - 0.875
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0.875 - 1.515
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1.515 - 2.155
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9. Into which class is the value 14.6 assigned? (Circle your answer)
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Class
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a.
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11.2 - 12.9
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b.
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12.9 - 14.6
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c.
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14.6 - 16.3
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10. What is the standard deviation for these data: 3.784, 3.784, and 3.784
Part B: True or False (11-27)
11. The random sample is the most important, because statistical theory applies to it alone.
12. In a frequency distribution, the class mark is the number of observations that fall within that class.
13. Original class interval frequencies can be obtained by multiplying the respective relative frequencies by the total number of observations.
14. The sum of the class frequencies is equal to the number of observations made.
15. Planning is the most important step in statistical studies.
16. Systematic, stratified and cluster sampling are not approximations to simple random sampling.
17. A relative frequency distribution describes the proportion of data values that fall within each category.
18. There would be no need for statistical theory if census, rather than a sample was always used to obtain information about populations.
19. A random variable is a variable that can take different values according to the outcome of an experiment, and it can be either discrete or continuous.
20. The median always exists in a set of numerical data.
21. means that A and B are mutually exclusive events.
22. Mutually exclusive events imply that if one event occurs, the other cannot occur. An event (e.g.,) and its complement are always mutually exclusive.
23. The mean of the discrete probability distribution for a discrete random variable is called its expected value.
24.When events are not mutually exclusive, the rule is:
25. Rule of addition when event are mutually exclusives:
26. The P(x) is always 0 ≤ P(x) ≤ 1.
27. Events are independent when the occurrence of one event has no effect on the probability that another will occur.
Part C: Multiple Choice (28-40)
Use the following data to answer question 28-33:
20 31 45 54 38 33 22 45 17
28. The Mode is
a. 33 b. 34 c. 38 d. 45
29. The 50th percentileis
a. 33 b. 35 c. 45.5 d. 45
30. The Mean is
a. 33.89 b. 34.89 c. 38.13 d. 32.13
31. The Variance is
a. 139.43 b. 162.11 c. 154.27 d. 149.07
32. The Standard deviation is
a. 11.81 b. 12.73 c. 12.42 d. 12.21
33. The Range is
a. 25 b. 28 c. 34 d. 37
Select the best answer for question 37-40 :
34. The simplest measure of dispersion is the
a. Standard deviation.
b. Variance.
c. Quartile deviation
d. Range
35. The largest value in a set of data is 240, and the lowest value is 100. If the resulting frequency distribution is to have seven classes of equal width, what will be the class width?
a. 12 b. 7 c. 5 d. 20
36. For the values 10, 20, 30, 40, and 50, the average absolute deviation from the mean is
a. 10 b. 15 c. 12 d. 14
37. A simple random sample for five executives who went on a diet on their doctor's order report the following numbers of pounds lost during their first two weeks on the diet: 5,8,3,7,8. What is the variance for this sample?
a. 4.7 b. 3.76 c. 1.94 d. 2.17
Part D: Must show all your work step by step in order to receive full credit; Excel is not allowed. (38-40)
38. Use the given information to answer the following questions:
a. Range
b. Variance
c. Standard deviation
39. The length of stay in a hospital for major surgery is recorded for a sample of 48 patients: (a-h)
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Length of Stay (Days)
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12
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13
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14
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15
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Patient Count
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22
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2
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8
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16
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a) Mean
b) Median
c)Mode
d) Range
e) Variance
f) Standard deviation
g) 95th Percentile
h) 3nd Quartile
40. Please fill and complete the following table, then answer the following questions (a-h). (**Using D-Method)
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Score
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Frequency
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Mid-point (X)
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Cf
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d
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df
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f
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-2
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-1
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0
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1
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2
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Total
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a) Mean
b) Median
c)Mode
d) Range
e) Variance
f) Standard deviation
g) 45th Percentile
h) 1st Quartile