Exam 3: Descriptive Statistics

A business analyst is considering a data set reflecting the number of products purchased at one time, there is a minimum of 45 and a maximum of 61.Given that the data set the number of products purchased for 5,791 purchases, the range would be ________.

It is inappropriate to use the mean to analyze data that are not at least interval level in measurement.

A company is reviewing the database of customer purchases over the past 3 years.Using descriptive statistics on this large data set, a business analyst found the following values. From this we can conclude that,

The empirical rule may only be applied when data are known to be normally distributed.

David Desreumaux, VP of Human Resources of Maritime Boat Manufacturing (MBM), is reviewing the employee training programs of MBM factories.His staff compiled the following table of provincial statistics on safety training hours: What can David conclude from these statistics?

Measures of variability include percentiles and quartiles.

An outlier of a data set is determined from the lower and upper quartile

A histogram can be used in business analytics to determine if a variable is approximately normally distributed.

The sum of the average of the squared deviations about the arithmetic mean, divided by the sample size minus one is called the sample variance.

The sum of deviations about the arithmetic mean for a given set of data is always equal to zero.

A commuter travels many kilometres to work each morning.She has timed this trip 5 times during the last month.The time (in minutes)required to make this trip was 34, 39, 41, 35, and 41.The mean time (in minutes)required for this trip was ___.

The lower the coefficient of variation value the lower the variability and thereby lower risk.

A commuter travels many kilometres to work each morning.She has timed this trip 5 times during the last month.The time (in minutes)required to make this trip was 44, 39, 41, 35, and 41.The mean time required for this trip was 40 minutes.What is the standard deviation for this sample data?

A box and whisker plot is determined from the mean, the smallest and the largest values, and the lower and upper quartile.

If the mean of a distribution is greater than the median, then the distribution is positively skewed.

The following measurements represent the gain or loss in the daily closing price of a security for ten consecutive days: -1, 3, 4, 1, 0, -4, -3, 2, -1, 1 The mean gain or (loss)was _____

Jessica Salas, President of Salas Products, is reviewing the warranty policy for her company's new model of automobile batteries.Life tests performed on a sample of 100 batteries indicated: (1)an average life of 75 months, (2)a standard deviation of 5 months, and (3)a bell shaped battery life distribution.Approximately 68% of the batteries will last between ___.

The average starting salary for graduates at a university is $25,000 with a standard deviation of $2,000.If a histogram of the data shows that it takes on a mound shape, the empirical rule says that approximately 68% of the graduates would have a starting salary between ___.

The approximate percentage number of values that lie with a given number of standard deviations about the mean is known as Chebyshev's theorem.

The following frequency distribution was constructed for the age of accounts receivable: The frequency distribution reveals that the accounts receivable ages are ___.