Exam 3: Descriptive Statistics

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 lowest appropriate level of measurement for the median is ordinal.

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

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

The ages of students in a class have been put into the frequency distribution below: What is the modal age of these students?

Compute the mean,median,mode,standard deviation,and variance of grouped data.

A statistics student made the following grades on 5 tests: 84,78,88,72,and 72.What is the median grade?

Skewness and kurtosis of a data set are measures of the shape of the distribution.

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

Manuel Banales,Marketing Director of Plano Power Plants Inc.'s Electrical Division,is leading a study to assess the relative importance of product features.Two items on a survey questionnaire distributed to 100 of Plano's customers asked them to rate the importance of "ease of maintenance" and "efficiency of operation" on a scale of 1 to 10 (with 1 meaning "not important" and 10 meaning "highly important").His staff assembled the following statistics on these two items: What can Manuel conclude from these statistics?

Average deviation is a common measure of the variability of data containing a set of numbers.

Pinky Bauer,Chief Financial Officer of Harrison Haulers,Inc. ,suspects irregularities in the payroll system,and orders an inspection of "each and every payroll voucher issued since January 1,2000." Each payroll voucher was inspected and the following frequency distribution was compiled: The mean number of errors per voucher 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 mean time (in minutes)required for this trip was ___.

A statistics student made the following grades on 5 tests: 84,78,88,78,and 72.What is the mean grade?

The ages of students in a class have been put into the frequency distribution below: What is the median age of these students?

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 mean number of points missed?

The mean life of a particular brand of light bulb is 1000 hours and the standard deviation is 50 hours.It can be concluded that at least 89% of this brand of bulbs will last between ___.

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?

The mean life of a particular brand of light bulb is 1000 hours and the standard deviation is 50 hours.We can conclude that at least 75% of this brand of bulbs will last between ___.

Statistical measures used to yield information about the centre or the middle parts of a group of numbers are called the measures of central tendency.