MBA 640 Concepts Midterm Exam

A variable is classified as ordinal if: a. there is a natural ordering of categories b. the data arise from continuous measurements c. we track the variable through a period of time d. there is no natural ordering of categories

a

Consider a population 2, 4, 3, 7. Fix the sample size as 3, we can list all possible samples. According to central limit theorem, the standard deviation/error of sample means is: a. 1.08 b. 4.7 c. 2.17 d. 3.5

a

Consider a population 3, 5, 5, 7. Fix the sample size as 2, we can list all possible samples. According to central limit theorem, the variance of sample means is: a. 1 b. 3 c. 2 d. 4

a

Cross-sectional data are observations: a. coming from different individuals or groups at a single point in time b. none of these c. combination of time series and panel data d. collecting at usually discrete and equally spaced time intervals

a

In statistics, a parameter a. is a descriptive measurement about a population b. is a descriptive measurement about a sample c. is both a and b d. is neither a or b

a

Suppose we are interested in political affiliation, a categorical variable that might assume three values - Republican, Democrat, or Independent. How many dummy variables should be constructed to represent political affiliation? a. 2 b. 4 c. 3 d. 1

a

Which group in the following is a sample? a. 5000 students at CMU b. Students at CMU during 2010-2012 c. Books sold at CMU book store d. Drivers in Mount Pleasant

a

A population consists of 14 observations. Fix the sample size as 4, if order is not important, the total number of possible samples using simply random sampling method is: a. 24040 b. 1001 c. 3632428800 d. 1000

b

In statistics, a population a. is chosen to represent a sample b. refers to the entire set of entities of interest in a study. c. is a part of a sample d. refers to some participants in an experiment

b

In statistics, a statistic a. is a descriptive measurement about a population b. is a descriptive measurement about a sample c. is both a and b d. is neither a or b

b

Numerical variables can be subdivided into which two types? a. Diverse and categorical b. Discrete and continuous c. Nominal and progressive d. Cross-sectional and discrete

b

Panel data are: a. observations collecting at usually discrete and equally spaced time intervals b. derived from a number of observations over time on a number of cross-sectional units c. observations coming from a different individuals or groups at a single point in time d. none of these

b

SPX daily closing prices during 6/1/2019-12/15/2019 are: a. panel data b. time series data c. all of these d. cross-sectional data

b

X follows a normal distribution with mean 20 and variance 4, when p=0.75, X is: a. 22.70 b. 21.35 c. 7.45E-07 d. 3.14E-22

b

player salary data for 10 MLB baseball teams during 2012-2019 are: a. time series data b. panel data c. all of these d. cross-sectional data

b

"number of children" is a: a. continuous variable b. dummy variable c. discrete variable d. nominal variable

c

A population consists of 10 observations. Set the sample size as 5. The total number of possible samples using systematic sampling method is: a. 3 b. 5 c. 2 d. 4

c

According to the central limit theorem, the sampling distribution of sample mean is approximately: a. t distributed b. standard normal c. normal d. f distributed

c

Evaluate the following expression: -1000 + 900*1.084 a. -432 b. -136.05 c. 224.44 d. 2,888

c

In statistics, the mean a. is the value that appears most often in a data set b. is the middle observation when the data are arranged from smallest to largest c. is the average of all values of a variable d. is all of above

c

In statistics, the standard deviation a. is the value that appears most often in a data set b. is the average of the squared deviations from the mean. c. is the square root of the variance. d. is both b and c.

c

P (-1<z<2.5) is: a. 0.8413 b. 0.9938 c. 0.8351 d. 0.1525

c

To represent a categorical variable with K different categories, the number of dummy variables needed is: a. 1 b. K c. K-1 d. 2

c

When p=0.95, the standard normal value Z is: a. 2.65 b. 3.65 c. 1.64 d. -1.64

c

X follows a normal distribution with mean 3 and variance 25, the probability of X being larger than 10 is: a. 0.39 b. 0.92 c. 0.08 d. 0.61

c

In statistics, a sample a. refers to the entire set of entities of interest in a study b. is a smaller group drawn from the population that has the characteristics of the entire population c. is a part of a population d. is both b and c

d

In statistics, the median a. is the value that appears most often in a data set b. is the middle observation when the data are arranged from smallest to largest when the number of observations in a data set is odd. c. is the average of the two middle observations when the number of observations in a data set is even. d. is both b and c

d

In statistics, the range a. is the value that appears most often in a data set b. is the average of all values in a data set. c. is the middle observations in a data set. d. is the difference between the largest and smallest values in a data set.

d

In statistics, the variance a. is the value that appears most often in a data set b. is the average of the squared deviations from the mean. c. is square of standard deviation. d. is both b and c.

d

The shape of a normal distribution is determined by: a. none b. both mean and variance c. mean d. variance

d