BA / 578 Midterm Exam I Summer II 2015

Online Exam I

Part A: True or False (1-10)

_______1. Original class interval frequencies can be obtained by multiplying the respective relative frequencies by the total number of observations

_______2.  Systematic, stratified and cluster sampling are not approximations to simple random sampling.

_______3.  is

_______4. The median always exists in a set of numerical data.

_______5.  means that A and B are mutually exclusive events.

_______6.  Mutually exclusive events imply that if one event occurs, the other cannot occur. An

event (e.g.,) and its complement are always mutually exclusive.

_______7.

_______8. When events are not mutually exclusive, the rule is:

_______9. Rule of addition when event are mutually exclusives:   

_______10. Events are independent when the occurrence of one event has no effect on the probability that another will occur.

Part B: Multiple Choice (11–22)

Please select the best answer for 11-15:

______ 11. For the data values, 20, 31, 45. 54, 38, 33, 22, 45, and 17, the mode is

a.       33              b. 34                c. 38                d. 45

______ 12. The simplest measure of dispersion is the

a. Standard deviation.             b. Variance.

c. Quartile deviation               d. Range

______ 13. The largest value in a set of data is 240, and the lowest value is 100. If the resulting frequency distribution is to have seven classes of equal width, what will be the class width?

a. 12                b. 7                  c. 5                  d. 20

______ 14. For the values 10, 20, 30, 40, and 50, the average absolute deviation from the mean is

a. 10                b. 15                c. 12                d. 14

______ 15. A simple random sample for five executives who went on a diet on their doctor’s order report the following numbers of pounds lost during their first two weeks on the diet: 5,8,3,7,8. What is the variance for this sample?

a. 4.7               b. 3.76             c. 1.94             d. 2.17

Questions 16-18 refer to the following frequency distribution:

The following information represents the number of tons of grain stored at the 60 grain elevators of central Soya, Inc.

Questions 19-22 refer to the following frequency distribution:

The following figures represent the weights of a sample of twelve women in the Richard Simmons Early Morning Exercise Class. Compute the requested statistics describing their weights (all in pounds).

1. Mean

1. Median

1. Mode

1. Sample Standard Deviation

Part C: Answer the following questions (23-30)

1. What is the most important step of statistical study?

1. Name 6 reasons why we use samples instead of an entire population.

1. Name 3 types of statistical samples

1. Name 5 measurement that we use to measure of spread or variability.

1. Name 3 measurement that we use to measure of central location.

1. Name 4 types of random samples.

1. What are stages for a statistical study?

30.  Why do we use regression? Please explain.

Part D: Must show all your work step by step in order to receive the full credit; Excel is not allowed. (31-43)

1. The following random sample of annual salaries was recorded. Units are in thousands of dollars. Please use the following data to answer the questions (a-h).

1. Use the information from problem number 4 on page 2-34 to answer the following questions (a-h).

1. Please compute and fill the following table. Then answer the following questions (a-h). (**Using D-Method)

1. Use the information from problem number 2 on page 3-42 and fill in the given table then answer the following questions (a-f). (**Using D-Method)

35.  Work on problem number 9 (a-b) on page 3-57

36.  Use the information from problem number 2 on page 4-10 and fill in the given table then answer the following questions (a-g).

37.  Work on problem number 16 (part a -c) on page 5-15

a)

b)

c)

38.  Work on problem number 5 (a-e) on page 6-17

39.  Work on problem number 14 (a-d) on page 6-19

40.  The following probability distribution table has been obtained for the number of customer arrivals during any given minute at a Beta Alpha supermarket. Please fill in the given table and answer the following questions (a-c).

a)      Compute the expected value.

b)      Compute the variance.

c)      Compute the standard deviation

41.  Using the standard normal distribution tables, determine the following probabilities and please draw the shading the area with details.

	Show your work	Please draw graph
a.	P
b.	P
c.	P
d.	P
e.	P
f.	P

42.  Work on problem number 1 (a-h) on page 7-23

43.  Work on problem number 12 (a-f) on page 7-24