QM 214 Module 1
the standard deviation of the population data set 3, 4, 5, 6, and 8 is
1.72
the standard deviation of the sample data set 3, 4, 5, 6, and 8 is
1.92
the mode for the data set: 4 4 5 6 9 9 is
4 & 9
Categorize the following measurements into: a. Nominal-level b. Ordinal-level c. Interval-level d. Ratio-level (indicate the level of measurement, choose from a~d, type ONLY "a" "b" "c" or "d").
An investor collects data on the weekly closing price of gold throughout a year. It is d A restaurant surveys its customers about the quality of its waiting staff on a scale of 1 to 4, where 1 is poor and 4 is excellent. It is b An analyst assigns a sample of bond issues to one of the following credit ratings, given in descending order of credit quality (increasing probability of default): AAA, AA, BBB, BB, CC, D. It is b The dean of the business school at a local university categorizes students by major (ie. accounting, finance, etc.) to help in determining class offerings in the future. It is a
After a test, John found out that he scored in the 80th percentile. This means
John scored as high as or higher than 80% of the students who took the test.
Categorize the following variables into: a. Qualitative b. Quantitative (indicate the type of variable, choose between a and b, and type ONLY "a" or "b")
Points scored in a football game. It is b Colors of cars in a mall parking lot. It is a Time it takes each student to complete a final exam. It is b Racial composition of a high school classroom. It is a
1. For each of the following, determine whether the group is a sample or a population. i. The participants in a study of a new cholesterol drug. _____ (choose between a and b). ii. The 30 stocks that form the Dow Jones Industrial Average index to represent the whole stock market. _____ (choose between a and b). a. Sample b. Population
a a
For a negatively skewed distribution, the variance is a negative number.
false
Mean can be computed for variables with ordinal-level measurements.
false
The average squared distance of data values from their mean is the standard deviation.
false
The sample mean is calculated by summing up all the values in the sample and dividing it by (n-1), where n is the number of values in the sample.
false
The measure of central location where half the values of the data set lie above this measure and half the values of the data set lie below this measure is know as the
median
The ____ is the measure of central location that also is the most frequently occurring value in the data set.
mode
A box plot is constructed using several different values. Which of the following values are included in a box plot:
the third quartile the smallest value the second quartile
For a population, the sum of the deviations from the population mean is 0.
true
For a sample, all values in the sample are used to compute the sample mean.
true
For a sample, the sum of the deviations from the sample mean is 0.
true
Mean cannot be computed for variables with nominal-level measurements.
true
Median can be found for variables with ordinal-level measurements.
true
Mode can be found for variables with nominal-level measurements.
true
The population mean is calculated by summing up all the values in the population and dividing it by N, where N is the number of values in the population.
true
The average squared distance of data values from their mean is the
variance
