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.