Exam 3: Descriptive Statistics

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 99.7% of the batteries will last between ___.

Liz Chapa manages a portfolio of 250 common stocks.Her staff compiled the following performance statistics for two new stocks: The coefficient of variation for Salas Products,Inc.is ___.

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 modal time required for this trip was ___.

The empirical rule says that approximately what percentage of the values would be within two standard deviations of the mean in a bell shaped set of data?

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 mean absolute deviation for this sample data?

Skewness indicates that a data distribution is symmetrical or asymmetrical.

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 95% of the graduates would have a starting salary between ___.

According to Chebyshev's Theorem,how many values in a data set will be within two standard deviations of the mean?

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?

Apply various measures of central tendency-including the mean,median,and mode-to a set of ungrouped data.

The most appropriate measure of central tendency for nominal-level data is the median.

In its Industry Norms and Key Business Ratios,Dun & Bradstreet reported that Q₁,Q₂,and Q₃ for 2,037 gasoline service stations' sales to inventory ratios were 20.8,33.4,and 53.8,respectively.From this we can conclude that ___.

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 variance for this sample data?

The sample standard deviation is calculated by taking the square root of the population standard deviation.

A measure of how peaked the data is,is called Kurtosis.

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

The most frequently occurring value in a set of data is called the mode.

An instructor is evaluating the performance of students on a test.He records the number of points that each student missed and created a frequency distribution.This is provided below: What is the variance for this population?

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

David Desreumaux,VP of Human Resources of Maritime Boat Manufacturing (MBM),is reviewing the employee training programs of MBM factories.His staff reports several statistics for safety training hours.The mean is 20 hours,the standard deviation is 5 hours,the median is 15 hours,and mode is 10 hours.The Pearsonian coefficient of skewness for safety training hours is ___.