Each of the following question worth 6 marks, please answer all of them. If needed please use Harvard referencing style. There is no word limit, but it is necessary that you provide answers with explanations.
Question 1:
Below are five questions from a survey of MBA students. Answers were written in the blank at the left of each question. For each question, state the data type (categorical, discrete numerical, or continuous numerical) and measurement level (nominal, ordinal, interval, ratio). Explain your reasoning. If there is doubt, discuss the alternatives.
1. What is your gender? (Male = 0, Female = 1)
2. What is your approximate undergraduate college GPA? (1.0 to 4.0)
3. About how many hours per week do you expect to work at an outside job this semester?
4. What do you think is the ideal number of children for a married couple?
5. On a 1 to 5 scale, which best describes your parents? (1 = Mother clearly dominant ? 5 = Father clearly dominant)
Question 2:
Below are monthly rents paid by 30 students who live off campus. (a) Find the mean, median, and mode. (b) Do the measures of central tendency agree? Explain. (c) Calculate the standard deviation. (d) Sort and standardize the data. (e) Are there outliers or unusual data values? (f) Using the Empirical Rule, do you think the data could be from a normal population?
|
730
|
730
|
730
|
930
|
700
|
570
|
|
690
|
1,030
|
740
|
620
|
720
|
670
|
|
560
|
740
|
650
|
660
|
850
|
930
|
|
600
|
620
|
760
|
690
|
710
|
500
|
|
730
|
800
|
820
|
840
|
720
|
700
|
Question 3:
Prof. Hardtack gave four Friday quizzes last semester in his 10-student senior tax accounting class.
a) Find the mean, median, and mode for each quiz.
b) Do these measures of center agree? Explain.
c) For each data set, note strengths or weaknesses of each statistic of center.
d) Are the data symmetric or skewed? If skewed, which direction?
e) Briefly describe and compare student performance on each quiz.
Quizzes:
• Quiz 1: 60, 60, 60, 60, 71, 73, 74, 75, 88, 99
• Quiz 2: 65, 65, 65, 65, 70, 74, 79, 79, 79, 79
• Quiz 3: 66, 67, 70, 71, 72, 72, 74, 74, 95, 99
• Quiz 4: 10, 49, 70, 80, 85, 88, 90, 93, 97, 98
Question 4:
A certain airplane has two independent alternators to provide electrical power. The probability that a given alternator will fail on a one-hour flight is .02. What is the probability that (a) both will fail? (b) Neither will fail? (c) One or the other will fail? Show all steps carefully.
Question 5:
Dave the jogger runs the same route every day (about 2.2 miles). On 18 consecutive days, he recorded the number of steps using a pedometer. The results were
|
3,450
|
3,363
|
3,228
|
3,360
|
3,304
|
3,407
|
3,324
|
3,365
|
3,290
|
|
3,289
|
3,346
|
3,252
|
3,237
|
3,210
|
3,140
|
3,220
|
3,103
|
3,129
|
(a) Construct a 95 percent confidence interval for the true mean number of steps Dave takes on his run. (b) What sample size would be needed to obtain an error of ± 20 steps with 95 percent confidence?
(c) Using Excel, plot a line chart of the data. What do the data suggest about the pattern over time? (For this question, please insert the excel graph into word file to submit only ONE file to the Moodle)