Intro to Statistics 200

Week 2 Homework

LANE Text Book

7.  . For the data from the 1977 Stat. and Biom. 200 class for eye color, construct: a. pie graph b. horizontal bar graph c. vertical bar graph d. a frequency table with the relative frequency of each eye color

a. pie graph

b. horizontal bar graph

c. vertical bar graph

d. a frequency table with the relative frequency of each eye color

 

Eye Color             Number of Students

Brown                   11

Blue                       10

Green                   4

Gray                      1

 

9.  Which of the box plots on the graph has a large positive skew?  Which has a large negative skew? (Attachment 1)

               

 

6.  6. You recorded the time in seconds it took for 8 participants to solve a puzzle. These times appear below. However, when the data was entered into the statistical program, the score that was supposed to be 22.1 was entered as 21.2.  You had calculated the following measures of central tendency: the mean, the median, and the mean trimmed 25%. Which of these measures of central tendency will change when you correct the recording error?

                Time Seconds

                15.2

                18.8

                19.3

                19.7

                20.2

                21.8

                22.1

                29.4

 

8. You know the minimum, the maximum, and the 25th, 50th, and 75th percentiles of a distribution. Which of the following measures of central tendency or variability can you determine? mean, median, mode, trimean, geometric mean, range, interquartile range, variance, standard deviation.

 

Please see website and below numbers in column D0 for questions 30 and 31

30. (AT) What is the mean number of correct responses of the participants after taking the placebo (0 mg/kg)?

31.(AT) What are the standard deviation and the interquartile range of the d0 condition? http://onlinestatbook.com/2/case_studies/adhd.html

D0           D15       D30        D60

57           48 64 62

27           42 48 49

32           39 34 30

31           23 25 34

34           36 42 38

38           34 40 36

71           61 59 77

33           36 42 51

34           41 36 45

53           57 67 42

36           32 29 43

42           48 50 57

26           48 44 36

52           39 57 58

36           36 36 35

55           48 57 60

36           35 30 33

42           39 36 49

36           32 41 33

54           48 65 59

34           35 35 35

29           28 40 37

33           27 43 45

33           40 44 29

 

Illowsky Text Book

78. Twenty five randomly selected students were asked the number of movies they watched the previous week. The results are as follows.

# Of Movies

Frequency

Relative Frequency

Cumulative Relative Frequency

0

5

 

 

1

9

 

 

2

6

 

 

3

4

 

 

4

1

 

 

 

a. Construct a histogram of the data.

b. Complete the columns of the chart.

 

80. If the data were collected by asking the first 111 people who entered the store, then the type of sampling is:

a. cluster

b. simple random

c. stratified

d. convenience

 

84.  Given the following box plot: (Attachment 2)

 

 

a. which quarter has the smallest spread of data? What is that spread?

b. which quarter has the largest spread of data? What is that spread?

c. find the interquartile range (IQR).

d. are there more data in the interval 5–10 or in the interval 10–13? How do you know this?

e. which interval has the fewest data in it? How do you know this?

 i. 0–2

ii. 2–4

iii. 10–12

iv. 12–13

v. need more information

 

88. Given the following box plots, answer the questions. (Attachment 3)

 

 

a. In complete sentences, explain why each statement is false.

i. Data 1has more data values above two than Data 2has above two.

ii. The data sets cannot have the same mode.

iii. ForData 1, there are more data values below four than there are above four.

b. For which group, Data 1 or Data 2, is the value of “7” more likely to be an outlier? Explain why in complete sentences.