Complete problems 2, 5, 10, and 12 on pages 15–16 of the Statistical Reasoning text. Use Word to record your answers. For problems which require calculations, please show your work in order to receive full credit.
#2 The subject of statistics is often divided into two parts: descriptive and inferential. Briefly describe each.
#5 is it possible to draw a correct statistical conclusion yet reach an incorrect research conclusion? Explain your answer.
#10 In one state, voters register as Republican, Demorcrat, or Independent and records of the total registration are kept. Which scale of measurement is used?
#12 With an interval scale, is it proper to consider that an increase of 20 points is twice as much as an increase of 10 points? Explain
Problems 2, 8, and 10 on pages 30 31
In order to answer number 2 you need the info from question 1.
#1 Students in introductory psychology were asked to name their favorite foreign food. Their responses were as follows:
Chinese Mexican Italian Greek
Mexican Italian Italian Chinese
Indian Chinese Chinese Greek
Mexican Indian Japanese Chinese
Mexican Chinese Chinese Mexican
Italian Chinese Mexican Chinese
(a) Organize the results into a frequency distribution. (b) On what measurement scale are these observations? (c) Does it matter in what order we arrange the categories?
#2 Students in introductory statistics were asked about their academic standings. They gave the following responses:
Freshman Junior Sophomore Junior
Sophomore Graduate Sophomore Junior
Sophomore Junior Sophomore Senior
Senior Senior Junior Sophomore
Sophomore Senior Senior Freshman
Junior Graduate Sophomore Senior
(a) Organize the results into a frequency distribution. (b) On what measurement scale are these observations? (c) How does this frequency distribution differ from that in Problem 1? Hint: Does it matter in what order we arrange the categories?
#8 Data 2A
44 35 20 40 38 52 29 36 38 38
38 38 41 35 42 50 31 43 30 41
32 47 43 41 47 32 38 29 23 48
41 51 48 49 37 26 34 48 35 41
38 47 41 33 39 48 38 20 59 37
29 44 29 33 35 58 41 38 26 29
32 54 24 38 38 56 56 48 34 35
26 26 38 37 57 24 44 62 29 41

(a) Construct a grouped frequency distribution with 20-22 as the apparent limits for the lowest class interval. The interval width should thus be 3. (b) Construct another frequency distribution for the same scores, again with a width of 3 for the class intervals, but begin with 18-20 as the lowest interval. (c) List the lower and upper real limits for each interval. (d) Compare the two distributions. Are they generally similar in the impression they give of the raw scores?

#10 Convert the Following proportions to percentages, preserving the accuracy in the proportion: (a) .73;. (b).09; (c) .666; (d) .07; (e) .008.

#6 (page 46)
(a) Construct a frequency histogram from the data for the Good Mood condition in Data 2B (problem 13) in Chapter 2. (b) Construct a frequency polygon from the same data.

Data 2B
SCORE GOOD MOOD BAD MOOD
155-159 1
150-154 2 2
145-149 4 7
140-144 7 12
135-139 12 10
130-134 14 7
125-129 25 4
120-124 23 3
115-119 18 0
110-114 20 2
105-109 12 1
100-104 8 0
95-99 3 1
90-94 2

n = 150 n = 50
#8 Construct a bar diagram for the data in Problem 1 of Chapter 2
#1 Students in introductory psychology were asked to name their favorite foreign food. Their responses were as follows:
Chinese Mexican Italian Greek
Mexican Italian Italian Chinese
Indian Chinese Chinese Greek
Mexican Indian Japanese Chinese
Mexican Chinese Chinese Mexican
Italian Chinese Mexican Chinese

Complete the following from the Statistical Reasoning text:
• Problems 4, 6, 12, and 16 on pages 59–60.
• Problems 2, 12, and 29 on pages 80–81.
Problems 4 through 8 concern a distribution of 10 scores. Nine of them are 3,5,9,1,9,2,0,3 and 9. The tenth score, the mystery score, is greater than 5, but it is not 9.
#4 On the basis of the information above, is it possible to determine the mode of the distribution of 10 scores? If yes, what is the mode? Explain.
#6 On the basis of the information above, is it possible to determine the mean of the distribution of 10 scores? if yes, what is the mean? Explain.
#12 A researcher finds that the mean of her distribution of measures is 120 and the median is 130. What can you say about the shape of the distribution?
#16 In the distribution depicted in Figure 4.2 omit the “8”. Recalculate (a) the mode, (b) the median, and (c) the mean. (d) which measure was most affected by the change? Why?
Figure 4.2

#2 For the History midterm exam scores in Table 2.2, find (a) the range and (b) the semiinterquartile range.

#12 A ninth grade science teacher gives a standard achievement test to his class and finds that X = 90 with Sx = 8. For a national sample of ninth graders, X = 75 with Sx = 14. (a) How do his students compare the national sample? (b) What do the data suggest for teaching science to this class?
#29 For the data in Table 2.1 use IBM SPSS to calculate the mean and standard deviation. (Refer to Section 5.6 to adjust the value for the standard deviation provided by IBM SPSS so that the SS are divided by n.)
Table 2.1

Complete the following problems from the Statistical Reasoning text.
• Problems 2, 4, 10, and 12 on pages 95–96.
• Problems 2 and 22 on pages 121–123.

#2 For normally distributed scores, what proportion of scores would fall: (a) above Z = + 1.00? (b)
Above Z= + 2.00? (c) above Z = +3.00 (d) below Z = -2.00? (e) below Z = – 3.00?

#4 For normally distributed scores, what proportion of scores would fall: (a) between Z = -1.00 and Z= + 1.00? (b) between Z= -2.00 and Z= + 2.00? (c) between Z = -3.00 and Z= + 3.00? (d) between Z = -0.75 and Z= + 1.25?

#10 Among normally distributed scores, what are the Z score limits that identify the central (a) 99% of scores? (b)95% of scores? (c) 50% of scores?

#12 At Smart University, all new freshmen are given an English proficiency exam during the week of registration. Scores are normally distributed with a mean of 70 and a standard deviation of 10. The University has decided to place the top 25% into honors English and the bottom 20% into remedial English. What scores separate the upper 25% and lower 20% of the students from the rest?
#2 Seven students made the following scores on two quizzes, X and Y:

Student: H I J K L M
Score on X 7 2 1 6 5 3
Sore on Y 7 6 12 4 3 10

(a) Construct a scatter diagram of the relationship between these two variables. What is the direction of the relationship? (b) Compute r to two decimals using the raw-score method.

#22 Calculating r with IBM SPSS. To learn how to use IBM SPSS, you do not need large data sets. You have already calculated r by the raw-score method in Problems 1,2,3. For practice, calculate r with IBM SPSS. Once you feel comfortable with the software, calculate r for the following problem. In numerous studies, psychologist and sociologist have found a positive correlation between exposure to violence in the media (e.g., television, movies) and acts of aggression toward others. (See Anderson et al., 2003; Christenson & Wood, 2006; Johnson et al., 2006 for a review). Suppose that you replicate the study with fifty 16 year old boys and measure the mean number of media exposure per week (X) and acts of aggression ( mild to severe) during the past year (Y). Your results are as follows. What is r?