Basic Statistics for Business and Economics - Chapter 1-4 Exam Questions with Answers.

Basic Statistics for Business and Economics - Chapter 1-4 Exam Questions with Answers Statistics - Correct Answers: The science of collecting, organizing, presenting, analyzing, and interpreting data to assist in making more effective decisions. Descriptive Statistics - Correct Answers: Methods of organizing, summarizing, and presenting data in an informative way. Inferential Statistics - Correct Answers: A decision, estimate, prediction, or generalization about a population, based on a sample. Population - Correct Answers: The entire set of individuals or objects of interest, or the measurements obtained from all individuals or objects of interest. Sample - Correct Answers: A portion, or part, of the population of interest. Qualitative Variable - Correct Answers: Characteristic being studied is non-numeric. Quantitative Variable - Correct Answers: Information is reported numerically. Discreet Variable - Correct Answers: Can only assume certain values, and there are usually "gaps" between values. Ex. Number of bedrooms in a house (1,2,3...) Continuous Variable - Correct Answers: Can only assume any value within a specified range. Ex. Pressure of a tire, height of students. Four Levels of Measurement - Correct Answers: Nominal, Interval, Ordinal, Ratio Nominal Level - Correct Answers: Data that is classified into categories and cannot be arranged in any particular order. Can only be classified and counted, with no particular order. Ex. What workers want (percentages) Interval Level - Correct Answers: Similar to the ordinal level, with the additional property that meaningful amounts of differences between data values can be determined. There is no natural zero point. Ex. Women's dress sizes ordered on a table. Ordinal Level - Correct Answers: Data arranged in some order, but the differences between data values cannot be determined or are meaningless. Represented by sets of labels or names (high, medium, low) that have relative values. Classified data can be ranked or ordered. Ex. Professor rating of Superior - Inferior. Ratio Level - Correct Answers: The interval level with an inherent zero starting point. Differences and ratios are meaningful for this level. "Highest" level of measurement. (Practically all quantitative data is recorded on the ratio level) Ex. Number of patients seen, sales calls made. Frequency Table - Correct Answers: A grouping of qualitative data into mutually exclusive classes showing the number of observations in each class. Bar Chart - Correct Answers: A graph in which the classes are reported on the horizontal axis and the class frequencies on the vertical axis. The class frequencies are proportional to the heights of the bars. Pie Chart - Correct Answers: A chart that shows the proportion or percent that each class represents of the total number of frequencies. Frequency Distribution - Correct Answers: A grouping of data into mutually exclusive classes showing the number of observations in each class. Relative Frequency - Correct Answers: Captures the relationship between a class total and the total number of observations. Class Interval - Correct Answers: Obtained by subtracting the lower limit of a class from the lower limit of the next class. Class Frequency - Correct Answers: The number of observations in each class. Class Midpoint - Correct Answers: A point that divides a class into two equal parts. This is the average of the upper and lower class limits. Histogram - Correct Answers: A graph in which the classes are marked on the horizontal axis and the class frequencies on the vertical axis. The class frequencies are represented by the heights of the bars and the bars are drawn adjacent to each other. Frequency Polygon - Correct Answers: Similar to a histogram, also shows the shape of a distribution. Consists of line segments connecting the class midpoints of the class frequencies. Parameter - Correct Answers: A measurable characteristic of a population Statistic - Correct Answers: A measurable characteristic of a sample. Arithmetic Mean - Correct Answers: Most widely used measure of location. All values are used, it is unique, the sum of the deviations from the mean is 0, is calculated by summing the values and dividing by the number of values. Population Mean - Correct Answers: For ungrouped data, is the sum of all the population values divided by the total number of population values. Sample Mean - Correct Answers: For ungrouped data, is the sum of all the sample values divided by the number of sample values. Median - Correct Answers: The midpoint of the values after they have been ordered from the smallest to the largest, or the largest to the smallest. Mode - Correct Answers: The value of the observation that appears most frequently. Symmetric Distribution - Correct Answers: Mode = Median = Mean "Zero Skewness" Positive Skewness - Correct Answers: Mode < Median < Mean Negative Skewness - Correct Answers: Mode > Median > Mean Dispersion - Correct Answers: Explains the spread of data. Measures include range, mean deviation, variance, and standard deviation. Range - Correct Answers: Largest Value - Smallest Value Mean Deviation - Correct Answers: The arithmetic mean of the absolute values of the deviations from the arithmetic mean. Variance - Correct Answers: The arithmetic mean of the squared deviations from the mean. Standard Deviation - Correct Answers: The square root of the variance. Population Variance - Correct Answers: 1. Find mean 2. Find difference between each observation and the mean, square that difference 3. Sum all the squared differences 4. Divide the sum of the squared differences by the number of items in the population. Sample Variance - Correct Answers: 1. Find mean 2. Find difference between each observation and the mean, square that difference 3. Sum all the squared differences 4. Divide the sum of the squared differences by the number of items in the population, -1. Empiricle Rule - Correct Answers: For a symmetrical, bell-shaped frequency distribution, approximately 68% of the observations will lie within +/- 1 standard deviation of the mean; about 95% of the observations will lie within +/- 2 standard deviations of the mean; and practically all (99.7%) will lie within +/- 3 standard deviations of the mean. Measures of Location - Correct Answers: Pinpoints the center of a distribution of data. 1. The arithmetic mean 2. The weighted mean 3. The median 4. The mode Arithmetic mean - Correct Answers: It is calculated by summing the values and dividing by the number of values. 1. All values are used. 2. The sum of the deviations from the mean is 0. Population mean - Correct Answers: The arithmetic mean of the entire population. Sample Mean - Correct Answers: The arithmetic mean of random sample values drawn from the population.