Download Standard Deviation - Business Statistics - Exam and more Exams Business Statistics in PDF only on Docsity!
Exam 1 Sept. 23, 1997, Quant II (22S:008) Form C
The 35 exam questions and answer sheet are both to be turned in to your Discussion Section instructor at the end of the exam. Code your name and ID number on the answer sheet. Code your Section number under OPTIONAL CODES in positions L M N. Please notice the Defective Question report page at the end of the exam.
- Which of the following statistics are resistant to outliers?
I. The mean II. The range III. The standard deviation A) I and II only B) I and III only C) II and III only D) I, II, and III E) None of the above.
- The professor of a statistics course graded her latest exam and found the mean to be 72 and the standard deviation to be 8. She then decided to rescale the scores by adding 5 points to each person's exam. What are the mean and standard deviation of the new scores? A) mean = 72, standard deviation = 8 B) mean = 72, standard deviation = 13 C) mean = 77, standard deviation = 8 D) mean = 77, standard deviation = 13 E) Cannot be determined from the information given.
- A step aerobics class is attended by 5 men and 15 women. The average weight of the men is 170 pounds and the average weight of the women is 130 pounds. What is the average weight of all 20 people (to the nearest lb.)? A) 140 lb. B) 150 lb. C) 160 lb. D) 187 lb. E) Cannot be determined from the information given.
- If you are interested in predicting future behavior of a meandering process, it would be more helpful to look at a histogram than a sequence plot. A) True B) False
- A large company has 500 female employees and 850 male employees. The CEO wants to compare the distribution of ages of the females to the males. What graphical displays would be the best for comparison? A) frequency histograms B) relative frequency histograms C) side-by-side Pareto Diagrams D) separate sequence plots for males and females E) sequence plots with different plotting symbols for males and females
- Observational studies are passive studies in which randomization is not used.
A) True B) False
- A company wants to get feedback from its workers via a questionnaire. The company asks for volunteers (anyone interested) to fill out the questionnaire. The results are then compiled and studied. True or false: This is an example of a probability survey. A) True B) False
- Which of the following data sets is longitudinal?
I. The heights of patients getting their physicals at the University Hospital on June 12th^ ,
II. Average weekly salaries for McDonalds workers from June 1995 to January 1996. III. The ages of the spectators at the Iowa vs. UNI game this fall.
A) I and III B) I and II C) I only D) II only E) None of them
- At the beginning of the semester, a large lecture class had 300 students. One week later, the class had 270 students. What is the percentage change? A) –11.11% B) –10.00% C) 10.00% D) 11.11% E) 90.00%
- Based on the following dotplots, which one of the following statements is true?
.
. :.. :.. +---------+---------+---------+---------+---------+------- Data Set 1 .. :. : :. +---------+---------+---------+---------+---------+------- Data Set 2 10.0 12.5 15.0 17.5 20.0 22.
A) The mean of Data Set 1 is larger than that of Data Set 2. B) The median of Data Set 1 is smaller than that of Data Set 2. C) The number of points in Data Set 1 is larger than that of Data Set 2. D) The median of Data Set 1 is larger than that of Data Set 2. E) None of the above are true.
- The following table displays the number of rugby shirts sold yesterday at the Land's End outlet: 99Size
What percentage of women’s shirts sold were size small (to the nearest percent)?
A) 11% B) 17% C) 24% D) 33% E) 46%
- Referring to the table in the previous question, what percentage of the large shirts sold were men’s (to the nearest percent)? A) 12% B) 29% C) 40% D) 48% E) 60%
Gender Small Medium Large Extra Large Total Women 12 9 23 6 50 Men 8 16 35 11 70 Total 20 25 58 17 120
- A random process is one that is as if the successive values are drawn from a well-mixed bowl of possible values each time replacing the value drawn and remixing before selecting the next. A) True B) False
- The sequence plot at the right displays the quarterly revenues for the Dayton- Hudson department stores over several years. It is best described as A) random B) meandering C) upward trend D) seasonal E) upward trend plus seasonal
- The sequence plot at the right displays the annual worldwide vehicle sales (in millions) for General Motors over several years. It is best described as A) random B) meandering C) upward trend D) seasonal E) downward trend
- The Pareto Diagram is a basic tool for visually separating the “vital few from the trivial many.” A) True B) False
- A dataset contains 36 values with a mean of 10.4 and a standard deviation of 2.2. The third data value is y 3 = 11.5. What is the standardized value corresponding to y 3?
A) −0. B) 0 C) +0. D) 1 E) None of the above.
123412341234123412341234123412341234 75 76 77 78 79 80 81 82 83
2500
1500
500 Quarter Year
Revenue
Quarterly Revenues of Dayton-Hudson, Inc.
1970 1980 1990
Year
Sales
- The frequency histogram at the right shows the distribution of the percentage changes in the daily stock prices of Chrysler Corp over 167 consecutive trading days. Based on this plot we can say that: A) the prices meandered around zero for these 167 days. B) the stock prices rose relative to the previous days price about as often as they dropped relative to the pre- vious days price. C) the stock price sequence could be described as random. D) the stock price sequence contains an upward trend. E) the stock price sequence contains a downward trend.
- The density histogram at the right is of the ages of the students in this class defined as age last birthday in years. There are 345 ages in the dataset. From this plot, which of the following gives the number of 19-year olds in the class? A) 45 B) 29 C) 154 D) 345 E) None of these is close to the correct answer.
- A dataset contains 29 values with a mean of 123.5 and a standard deviation of 3.7. If all of the data values are doubled what are the new mean and standard deviation? A) mean = 123.5, standard deviation = 7. B) mean = 247, standard deviation = 3. C) mean = 123.5, standard deviation = 3. D) mean = 247, standard deviation = 7. E) None of the above.
- Dr. W. Edwards Deming is considered the father of scientific management.
A) True B) False
-6.0-4.5-3.0 -1.5 0.0 1.5 3.0 4.5 6.0 7.
50
40
30
20
10
0
% Change
Frequency
16.517.518.519.520.522.5 25.5 35.
Age
Density
- The two relative frequency histograms at the right are based on 75 and 256 data points, respectively. Which one of the following statements is true? A) Dataset 1 has larger mean but smaller standard deviation. B) Dataset 2 has larger mean but smaller standard deviation. C) Dataset 1 has larger mean and larger standard deviation. D) Dataset 2 has smaller mean and smaller standard deviation. E) None of the above can be determined from the information given.
- The density histogram at the right displays the distribution of heights of the 220 males in this class. The mean is 71.3 inches and the standard deviation is 2.7 inches. About what percentage of the heights fall above 74 inches? (Notice that the distribution is quite mound-shaped.) A) 16% B) 32% C) 68% D) 84% E) 95%
- A data set consists of 100 observations. If 30 of the observations are in the class interval from 20 to 25, what is the density associated with this class interval? A) 0. B) 0. C) 0. D) 30 E) None of the above.
- A process is a sequence of steps taken to acheive a goal.
A) True B) False
21.522.323.123.924.725.526.327.127.9 28.
40 30 20 10 0 Dataset 1
Relative Frequency (%)
2 4 6 8 10 12 14 16 18 20
30
20
10
0 Dataset 2
Relative Frequency (%)
60 70 80
Height
Density
Heights of Males in 22S:
Defective Question Report
Name:_____________________________________________________________________ Section:_______________________ ID: __________________________
If you believe that a test question is defective in some way, please list your complaint here. All complaints will be considered in our interpretation of the test results.
To correctly identify the test question we must know which form of the test you have taken. We also must know how you answered the question.
Remove this last page from the exam questions and turn it in to one of the instructors in the course.
Form (circle one): A B C D E
Question number: _____ Your choice of answer on answer sheet: ____ Your complaint:
Question number: _____ Your choice of answer on answer sheet: ____ Your complaint:
Question number: _____ Your choice of answer on answer sheet: ____ Your complaint:
