Statistics Homework

Instructions: Solving a mathematical or scientific problem is an exercise in logical and critical thinking. The process in coming up with the correct solution is much more important than the correct answer itself. Therefore, it is important to show that you understand the problems by showing your work, including calculations and methodologies. You will not receive full credit if you cannot convince your instructor that you actually know how to solve the problems.

Lane Questions http://onlinestatbook.com/Online_Statistics_Education.pdf

1. Chapter 2, Exercise 7, Page 117

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

2. Chapter 2, Exercise 9, Page 118

Which of the box plots on the graph has a large positive skew? Which has a large negative skew?

3. Chapter 3, Exercise 6, Page 159

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?

4. Chapter 3, Exercise 8, Page 160

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

5. Chapter 3, Exercise 30, Page 163

ADHD Treatment (AT) case study

http://onlinestatbook.com/2/case_studies/adhd.html

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

6. Chapter 3, Exercise 31, Page 163

ADHD Treatment (AT) case study http://onlinestatbook.com/2/case_studies/adhd.html

(AT) What are the standard deviation and the interquartile range of the d0 condition?

Illowsky Questions https://d3bxy9euw4e147.cloudfront.net/oscms-prodcms/media/documents/Introductory_Statistics-OP.pdf

7. Chapter 2, Exercise 78, Page 138

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.

8. Chapter 2, Exercise 80, Page 139

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

9. Chapter 2, Exercise 84, Page 140

Given the following box plot:

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

10. Chapter 2, Exercise 88, Page 142

Given the following box plots, answer the questions.

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.

11. Descriptive Statistics

My colleagues and good friends taught STAT 200 in Europe. Both had ten students in their respective classes, sections 6980 and 6981. Below please find their evaluation by their students on their overall satisfaction with the class. The students ranked their level of satisfaction from 1 to 5, 1 being the lowest, and 5 the highest.

Now, let's see if we can summarize the student evaluation results the old fashion way. Let us go after the usual suspects such as the mean, median, mode, and range first.

a. What is the mean evaluation score of each professor?

b. What is the median evaluation score of each professor?

c. Can we tell from these numbers which instructor was more popular with the students? And why do you think so?

d. How about the standard deviation? Do you think we can make some more intelligent statements when we have the standard deviations?

e. Now, what kind of stories can we tell?