Exam 4: Descriptive Statistics

A national survey showed that most commuter cars contain only the driver.Hungry for a story,a campus newspaper reporter asked five randomly chosen commuter students how many occupants,including the driver,rode to school in their cars.Their responses were 1,1,1,1,and 6.The next day a story appeared in the paper headlined "University Commuters Double National Average Ridership." Is this a reasonable assessment of central tendency? How would you characterize the variability of the sample?

A smooth distribution with one mode is negatively skewed (skewed to the left).The median of the distribution is $65.Which of the following is a reasonable value for the distribution mean?

Frieda is 67 inches tall and weighs 135 pounds.Women her age have a mean height of 65 inches with a standard deviation of 2.5 inches and a mean weight of 125 pounds with a standard deviation of 10 pounds.In relative terms,it is correct to say that

Referring to this graph of ice cream fat content,the second quartile is between 60 and 61.

A platykurtic distribution is more sharply peaked (i.e. ,thinner tails)than a normal distribution.

Here are statistics on order sizes of Megalith Construction Supply's shipments of two kinds of construction materials last year. Which order sizes have greater variability?

Which of the following is not a valid description of an outlier?

Briefly describe this sample of departure delays on American Airlines flights out of Denver over a seven-day period,March 3−9 (n = 149 flights).

The midrange is not greatly affected by outliers.

The range as a measure of variability is very sensitive to extreme data values.

Here are advertised prices of 21 used Chevy Blazers.Describe the distribution (center,variability,shape).

The values of xmin and xmax can be inferred accurately except in a

A leptokurtic distribution is more sharply peaked (i.e. ,thinner tails)than a normal distribution.

John scored 85 on Prof.Hardtack's exam (Q1 = 40 and Q3 = 60).Based on the fences,which is correct?

Consider the following data: 6,7,17,51,3,17,23,and 69.The range and the median are

A certain health maintenance organization examined the number of office visits by its members in the last year.For this data set,the mean is probably not a very good measure of a "typical" person's office visits.

Which is a characteristic of the trimmed mean as a measure of center?

Estimating the mean from grouped data will tend to be most accurate when

Briefly describe these data.Sketch its box plot and describe the sample succinctly.

Which two statistics offer robust measures of center when outliers are present?