Essentials of Statistics for Business and Economics Chapter 3 Exam Questions with Answers.

Essentials of Statistics for Business and Economics Chapter 3 Exam Questions with Answers Sample statistic - Correct Answers: a numerical measure that describes an aspect of a sample population parameter - Correct Answers: a numerical measure that describes an aspect of a population point estimator - Correct Answers: the sample statistic when used to estimate the corresponding population parameter mean - Correct Answers: A measure of central location computed by summing the data values and dividing by the number of observations. median - Correct Answers: A measure of central location provided by the value in the middle when the data are arranged in ascending order. mode - Correct Answers: a measure of location, defined as the value that occurs with greatest frequency percentile - Correct Answers: A value such that at least p percent of the observations are less than or equal to this value and at least (100 - p) percent of the observations are greater than or equal to this value. quartiles - Correct Answers: The 25th, 50th, and 75th percentiles, referred to as the first quartile, the second quartile (median), and third quartile, respectively. The quartiles can be used to divide a data set into four parts, with each part containing approximately 25% of the data. range - Correct Answers: a measure of validity, defined to be the largest value minus the smallest value interquartile range (IQR) - Correct Answers: A measure of variability, defined to be the difference between the third and first quartiles. variance - Correct Answers: a measure of variability based on the squared deviations of the data values about the mean standard deviation - Correct Answers: A measure of variability computed by taking the positive square root of the variance. coefficient of variation - Correct Answers: A measure of relative variability computed by dividing the standard deviation by the mean and multiplying by 100. skewness - Correct Answers: A measure of the shape of a data distribution. Data skewed to the left result in negative skewness; a symmetric data distribution results in zero skewness; and data skewed to the right result in positive skewness. z-score - Correct Answers: a value computed by dividing the deviation about the mean by the standard deviation s. Referred to as a standardized value and denotes the number of standard deviations xi is from the mean Chebyshev's Theorem - Correct Answers: A theorem that can be used to make statements about the proportion of data values that must be within a specified number of standard deviations of the mean. Empirical rule - Correct Answers: A rule that can be used to compute the percentage of data values that must be within one, two, and three standard deviations of the mean for data that exhibit a bell-shaped distribution. Outlier - Correct Answers: An unusually small or unusually large data value. five-number summary - Correct Answers: An exploratory data analysis technique that uses five numbers to summarize the data: smallest value, first quartile, median, third quartile, and largest value. box plot - Correct Answers: A graphical summary of data based on a five-number summary. covariance - Correct Answers: A measure of linear association between two variables. Positive values indicate a positive relationship; negative values indicate a negative relationship correlation coefficient - Correct Answers: a measure of linear association between two variables that takes on values between -1 and 1. Values near 1 indicate a strong positive relationship; values near -1 indicate a strong negative linear relationship; and values near zero indicate the lack of a linear relationship