Part A:
Some questions in Part A require that you access data from Statistics for People Who (Think They) Hate Statistics. This data is available through the Student Textbook Resources link.
1. By hand (without using SPSS), compute the mean, median, and mode for the following set of 40 reading scores:
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31
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32
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43
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42
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24
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34
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25
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44
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23
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43
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24
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36
|
|
25
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41
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23
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28
|
|
14
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21
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24
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17
|
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25
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23
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44
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21
|
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13
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26
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23
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32
|
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12
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26
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14
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42
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14
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31
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52
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12
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23
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42
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32
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34
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2. Compute the means for the following set of scoresusing IBM SPSS software. The data sets can be found through the Sage Materials in the Student Textbook Resource Access link, listed under Academic Resources. The following set of scores are saved as Ch. 2 Data Set 3. Copy and paste the output from IBM SPSS into this worksheet.
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Hospital size (number of beds)
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Infection rate (per 1,000 admissions)
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234
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1.7
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214
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2.4
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165
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3.1
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436
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5.6
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432
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4.9
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342
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5.3
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276
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5.6
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187
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1.2
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512
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3.3
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553
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4.1
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3. You are the manager of a fast food store. Part of your job is to report which special is selling best to the boss at the end of each day. Use your knowledge of descriptive statistics and write one paragraph to let the boss know what happened today. Use the following data. Donot use IBM SPSS software to compute thestatistics needed; rather, do it by hand. Include a copy of your work.
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Special number
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Sold
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Cost
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Huge Burger
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20
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$2.95
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Baby Burger
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18
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$1.49
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Chicken Littles
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25
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$3.50
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Porker Burger
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19
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$2.95
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Yummy Burger
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17
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$1.99
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Coney Dog
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20
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$1.99
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Total specials sold
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119
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4. Suppose you are working with a data set that has some different (much larger or much smaller than the rest of the data) scores. What measure of central tendency would you use and why?
5. For the following set of scores, compute the range, the unbiased and the biased standard deviations, and the variance. Do the exercise by hand.
31, 42, 35, 55, 54, 34, 25, 44, 35
Why is the unbiased estimate greater than the biased estimate?
6. Use IBM SPSS software to compute all the descriptive statistics for the following set of three test scores over the course of a semester. Which test had the highest average score? Which test had the smallest amount of variability?
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Test1
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Test2
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Test3
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50
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50
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49
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48
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49
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47
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|
51
|
51
|
51
|
|
46
|
46
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55
|
|
49
|
48
|
55
|
|
48
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53
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45
|
|
49
|
49
|
47
|
|
49
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52
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45
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|
50
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48
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46
|
|
50
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55
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53
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7. This practice problem uses the data contained in the file named Ch. 3 Data Set 3. There are two variables in this data set.The data sets can be found through the Sage Materials in the Student Textbook Resource Access link, listed under Academic Resources. Using IBM SPSS software, compute all of the measures of variability you can for height and weight. Copy and paste the output from IBM SPSS into this worksheet.
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Variable
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Definition
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Height
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Height in inches
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Weight
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Weight in pounds
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8. Review the following frequency distribution. Create a histogram either by hand or by using some other application such as a Microsoft Excel document. Copy and paste the histogram into this document
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Class interval
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Frequency
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90-100
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12
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80-89
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14
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70-79
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20
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60-69
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24
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50-59
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28
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40-49
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29
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30-39
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21
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20-29
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15
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10-19
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17
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0-9
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12
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9. Identify whether these distributions are negatively skewed, positively skewed, or not skewed at all and why.
a. This talented group of athletes scored very high on the vertical jump task.
b. On this incredibly crummy test, everyone received the same score.
c. On the most difficult spelling test of the year, the third graders wept as the scores were delivered.
10. For each of the following, indicate whether you would use a pie, line, or bar chart, and why.
a. The proportion of freshmen, sophomores, juniors, and seniors in a particular university - pie
b. Change in GPA over four semesters
c. Number of applicants for four different jobs
d. Reaction time to different stimuli
e. Number of scores in each of 10 categories
Part B: Complete the questions below. Be specific and provide examples when relevant.
Salkind (2014) describes statistics as a set of tools. How do behavioral scientists use those tools?
How would you use descriptive statistics to report the effectiveness of a baseball team? How would you use inferential statistics to report the effectiveness of a baseball team? In this example, what is the sample and what is the population?
What does a measure of central tendency tell us about a data set? Identify the three common measures of central tendency used in descriptive statistics and give an example of each. How do you calculate them?
What is variability in a data set? Identify three measures of variability used in descriptive statistics, explain how to calculate each, and give an example of each.