Math Homework

1) Name some ways to graph quantitative variables and some ways to graph qualitative variables.

3) An experiment compared the ability of three groups of participants to remember briefly-presented chess positions. The data are shown below. The numbers represent the number of pieces correctly remembered from three chess positions.

Create side-by-side box plots for these three groups. What can you say about the differences between these groups from the box plots?

Non-players	Beginners	Tournament players
22.1	32.5	40.1
22.3	37.1	45.6
26.2	39.1	51.2
29.6	40.5	56.4
31.7	45.5	58.1
33.5	51.3	71.1
38.9	52.6	74.9
39.7	55.7	75.9
43.2	55.9	80.3
43.2	57.7	85.3

 

5) In a box plot, what percent of the scores are between the lower and upper hinges?

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

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?

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

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?

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.

Use the following information to answer the next two exercises: Suppose one hundred eleven people who shopped in a special t-shirt store were asked the number of t-shirts they own costing more than $19 each.

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:

 

Figure 2.41

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.

Figure 2.45

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

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

ii. The data sets cannot have the same mode.

iii. For Data 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