b. I chose the number of classes based on the Sturges’ Rule table. I knew I had 80 observations so that put me between either 7 or 8 classes. I chose 8 for both because that allowed the data to completely taper off at the very ends of the data; meaning the extremely low values were caught within the first and the last classes. I chose the width of the classes by taking the lowest value minus the highest value and then dividing that number by the amount of classes I intended on using. For example, in the MPG histogram I took 44 minus 11 and then divided by 8. That gave me about 4.13 so I rounded up to five to make all the numbers whole numbers. c. In the MPG histogram the central tendency is from 16 to 31. Over 78% of the data is within that range. This histogram is evenly distributed with an average “bell shaped curve”. This histogram is also evenly dispersed throughout the data. There are some extremely low values as well as some extremely high values with one modal class and several classes fairly evenly increasing and decreasing on either side of it. The Weight histogram is also fairly evenly distributed. It has a slight dip in the middle of the data, but overall it increases in the middle of the data and decreases towards the end of the data. The central tendency is from 1780 to 3700, where over 78% of the data lies. The dispersion in the weight histogram is also pretty even with some extremely low values and some extremely high values. The modal class is from 2740 to 3220 and the classes on either side of it are evenly decreasing. 2.

...Page 1 of 3
ASSIGNMENT 2ND SEMESTER : STATISTICAL ANALYSIS (STAT) STUDY UNITS COVERED DUE DATE TOTAL MARKS : CHAPTERS 1 - 8 : 3.00 p.m. 17 AUGUST 2010 : 100
INSTRUCTIONS TO CANDIDATES FOR COMPLETING AND SUBMITTING ASSIGNMENTS
The complete ‘Instructions to Students for Completing and Submitting Assignments’ must be collected from any IMM GSM office, the relevant Student Support Centre or can be downloaded from the IMM GSM website. It is essential that the complete instructions be studied prior to commencing your assignment. The following points highlight only a few important notes. 1) You are required to submit ONE assignment per subject. 2) The assignment will contribute 20% towards the final examination mark, and the other 80% will be made up from the examination, however the examination papers will count out of 100%. 3) Although your assignment will contribute towards your final examination mark, you do not have to earn credits for admission to the examinations; you are automatically accepted on registering for the exam. 4) Number all the pages of your assignment (e.g. page 1 of 4) and write your name and surname, student number and subject at the top of each page. 5) The IMM GSM requires assignments to be presented on plain A4 paper. You must show all working calculations, including and where appropriate multiple choice working calculations. 6) A separate assignment cover, which is provided by the IMM GSM, must be attached to the front cover of each...

...Displaying categorical data HW
3.1 Each person in a nationally representative sample of 1252 young adults age 23 to 28 years old was asked how they viewed their “financial physique” (“2009 Young Adults & Money Survey Findings,” Charles Schwab, 2009). “Toned and fit” was chosen by 18% of the respondents, while 55% responded “a little bit flabby,” and 27% responded “seriously out of shape.” Summarize this information in a pie chart.
3.3 A survey conducted by Robert Half Technology appeared in USA Today (October 22, 2009) “Whistle – Don’t Tweet – While you Work,” (www.roberthalhtechnology.com). One questions asked: “Which of the following most closely describes your company’s policy on visiting social networking sites, such as Facebook, MySpace and Tweeter, while at work? The responses are summarized in the following table:
Response category
Relative Frequency (expressed as percent)
Prohibited completely
54%
Permitted for business purposes only
19%
Permitted for limited personal use
16%
Permitted for any type of personal use
10%
Don’t know/no answer
1%
a. Explain how the survey response categories and corresponding relative frequencies were used or modified to produce the following table:
b. Using the original data in the table, construct a segmented bar graph.
c. What are two other types of graphical displays that would be appropriate for summarizing these data
3.8 The report “Findings from the 2008 Administration of the College Senior Survey”...

...
Revised 02/03/2010
2201_Quiz1A.docm
5. The bar chart below shows the relative frequency of 60 million women, by
educational attainment, who gave birth to a child in 1998. (Note: the percents do
not total 100%)
5A. What percent of these women had an associate degree?
•
•
•
•
15%
12.5%
7.5%
5%
5B. How many women with a Master’s degree gave birth in 1998?
•
•
•
•
30 million
300 thousand
3 million
4.5 million
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Revised 02/03/2010
2201_Quiz1A.docm
6. The following frequency histogram represents the IQ scores of a random
sample of seventh grade students. IQs are measured to the nearest whole
number. The frequency of each class is labeled above each rectangle.
6A. How many students were measured?
•
•
•
•
60
160
215
220
6B. What is the category width?
•
•
•
•
100
10
60
5
6C. What category had the highest frequency? (This is the mode.)
•
•
•
•
57
70-80
100-110
140-150
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2201_Quiz1A.docm
6D. What is the best description of this histogram?
•
•
•
•
Uniform
Symmetric
Skewed left
Skewed right
7. For the stem and leaf plot shown below:
Stem
8
7
6
5
4
Leaves
238
011366
345889
22399
047
7A. How many leaves are there?
•
•
•
•
5
23
28
10
7B. What are the min and the max?
•
•
•
•
47, 88
4, 8
40, 82
40, 88
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2201_Quiz1A.docm
8. The following data represent the flight time (in minutes) of a random sample
of seven flights between the same two cities.
282, 270, 260,...

...Briefly describe the distribution of class sizes including mention of sample size, centre, spread and shape.
b) There have been frequent complaints about large classes. Using the information above, discuss whether announcing that ‘the average class size is 21’ gives a fair impression of class sizes in Victoria.
c) Determine the value of the Inter-Quartile Range for this data.
d) Explain the difference between the standard deviation and the standard error for this data.
e) Briefly explain the meaning of the 95% confidence interval in this context.
Solution:
a) The sample size is 50; the mean class size is 21.8 which is less than the median 23.45.
This indicates a negative skew, also seen in the boxplot and histogram. No outliers are present.
Spread: Classroom sizes range from 9 to 28.5. The stdev is 5.464.
Shape: Note the large group of classes at the top end of the scale.
b) Not really a fair impression as the data are negatively skewed; the median may be more appropriate. The range would also be of interest here, perhaps more so than measures of centre for new teachers.
c) IQR = 26.65 – 17.1 = 9.55
d) The StDev measures variation in the raw data, the standard error measures variation (expected) in sample means (based upon samples of n = 50).
SE Mean = StDev ( (n
e) There is a 95% chance that the true mean class size is between 20.249 and 23.355.
4. The graphs below...

...Descriptive Statistics
QNT/561
July 29, 2014
Descriptive Statistics
Job Satisfaction
Central Tendency: Mean=8.5 JDI
Dispersion: Standard Deviation=1.16 JDI
Number: 139
Min/Max: 7 to 10 JDI
Confidence Interval: 8.36 to 8.75 JDI
*JDI=Job Descriptive Index
Months of Employment
Central Tendency: Mean= 136.24 Months
Dispersion: Standard Deviation= 117.26 Months
Number: 139
Min/Max: 1 to 359 Months
Confidence Interval: 116.74 to 155.73 Months
Descriptive Statistics Interpretation
Interpretation
Months of Employment
CHJ made a decision to choose 139 random employees. Their months of employment varied between a range of 1 and 359 days the employees estimated months employed with the company was around their months of employment were 136 days, either adding or subtracting 28 days , Nearly half of counted to be 136 days. CHJ strongly believes a 95% population months of employment average is between 116 and 165 days.
Job satisfaction
CHJ carefully selected One hundred employees the range was between 7 and 10. Half of the employees choose 8.75 which meant they were satisfied with their job. The other employees who were surveyed choose 8.6 which mean they were satisfied but CHJ could do a little more improvements.
Appendix A
Raw data used in the analysis
Appendix B
Charts and Tables
Frequency of Male and Female Employees by Department
Legend: Blue=Males Red=Females
Appendix C...

...Statistics 5371 Final Exam Review Fall 2012.
1. Suppose a researcher wants to design a new study with a power of 0.8 and a significance of 0.05 to test whether the caffeine content for a brand of coffee is really 100mg. A previous study gave a mean caffeine level for this brand of 110 mg and a standard deviation of 7 mg. Use PROC POWER to determine how many cups of coffee need testing.
2. A company did a study to estimate the effect of different promotional strategies on the market share of one of their products. Over a period of 36 months they varied their promotional strategy. There are four strategies: Ordinary (standard pricing and advertising); Discount (price discount with standard advertising); Promotion (standard pricing, enhanced advertising); and Both (price discount with enhanced advertising). Each month one of the strategies was employed and the market share (the percentage of purchasers of the given product type that selected the company's product). Higher market share is better for the company. The table below records the number of months in which each strategy was used (n) and a summary of the market share results in those months.
|Strategy |Pricing |Advertising |n |mean |SD |
|Ordinary |standard |standard |8 |2.40 |0.12 |
|Discount |Discount...

...WILMINGTON UNIVERSITY
CLASS INFORMATION & SCHEDULE
FACULTY MEMBER: TERM:
COURSE TITLE:
COURSE NUMBER: MBA 6100
OFFICE HOURS/METHOD OF CONTACT:
I. METHODOLOGY:
A. Teaching Methods: Distance learning course
Announcements and instructor guidance; assigned readings; homework problems, chapter information, textbook power point files, and case study.
This course requires stable and regular access to the internet as well as students’ ability to work independently and possess functional computer skills including proficiency with Microsoft Office. The course requires assignments completed on a weekly basis.
B. Pre-requisites
a. 6 credits of undergraduate accounting OR Wilmington University course MHR 7830 Accounting & Finance for Managers. Students are expected to have a basic understanding of financial accounting.
b. Proficiency with Microsoft Excel software.
C. Course details
a. Assignments and other course activities are required to be completed weekly.
b. The online week starts Monday and ends Sunday night, 11:59 pm EST.
c. All homework, case study, and exam preparation is required to be individual work.
d. Questions about homework and other course-related items are to be posted on the discussion board so that all students have an opportunity to read them. Often many students may have the same question. With the exception of items posted on Saturday or Sunday, expect replies in the form of a discussion post or Blackboard...

...CGE13101 Understanding Society Through Statistical Reasoning
Tutorial 3
1. A wholesale appliance distributing firm wished to study its accounts receivable for two successive months. Two independent samples of 50 accounts were selected for each of the two months. The results have been summarized below.
Frequency distribution for accounts receivable
Amount
March Frequency
April Frequency
$0 - under $2,000
$2,000 - under $4,000
$4,000 - under $6,000
$6,000 - under $8,000
$8,000 - under $10,000
$10,000 - under $12,000
6
13
17
10
4
0
10
14
13
10
0
3
Totals
50
50
Plot the frequency histogram for each month.
2. For the data below, reporting employees’ absences in a particular department during a three-month period, determine the values of the mean and median. The number of days absent is reported to the nearest half-day.
Employee Number
ID of days absent
001 5.0
002 0.0
003 1.5
004 3.0
005 1.0
006 2.0
007 9.0
008 5.5
009 1.0
010 4.0
011 2.0
012 2.0
3. Comment upon and interpret the differences in the values of the mean and median computed in Question 2. Which of these values best represents the “typical” number of days that employees were absent?
4. Which measure of central tendency would be most useful in each of the following instances?
(a) The production manager for a manufacturer of glass...