Exam 3: Describing Data Using Numerical Measures

A recent study in the restaurant business determined that the mean tips for male waiters per hour of work are $6.78 with a standard deviation of $2.11.The mean tips per hour for female waiters are $7.86 with a standard deviation of $2.20.Based on this information,which of the following statements do we know to be true?

The following data reflect the number of customers who test drove new cars each day for a sample of 20 days at the Redfield Ford Dealership. Given these data,what is the range?

A store manager tracks the number of customer complaints each week.The following data reflect a random sample of ten weeks. The range for these data is 8.

When the median of a data set is 110 and the mean is 127,the percentile associated with the mean must be higher than 50 percent.

A store manager tracks the number of customer complaints each week.The following data reflect a random sample of ten weeks. The variance for these data is approximately 27.78.

A distribution has a coefficient of variation of 65 percent and mean of 74.What is the value of the standard deviation?

If a data set has 1,133 sorted values,what value corresponds to the 3^rd quartile?

A dairy farm in Wisconsin bottles milk in one gallon containers.At a recent meeting,the production manager asked top management for a new filling machine that he argued would assure that all containers had exactly one gallon of milk.Based on sound statistical principles,the top management group should conclude that the production manager could have merit to his argument.

When news articles report on household income level they usually report the median income,rather than the mean income.This would be because income is usually a right-skewed distribution.

Which of the following is the most frequently used measure of variation?

A report on spending by adults on recreation stated the following: At least 75 percent of the people in the survey spend between $750 and $1,250 per year.The report also said that at least 88 percent spend between $625 and $1,375 per year.Given this information,which of the following is most apt to be true?

You are given the following data: Assuming that these data are a sample selected from a larger population,the median value for these sample data is 25.5.

The distribution of dollars paid for car insurance by car owners in a major east coast city is bell-shaped with a mean equal to $750 every six months and a standard deviation equal to $100.Based on this information we can use Tchebysheff's theorem to determine the conservative percentage of car owners that will pay between $550 and $950 for car insurance.

You are given the following data: Assuming that the data reflect a sample from a larger population,the sample mean is 30.00.

If after graphing the data for a quantitative variable of interest,you notice that the distribution is highly skewed in the positive direction,the measure of central location that would likely provide the best assessment of the center would be the median.

A set data in which the mean,median,and mode are all equal is said to be a skewed distribution.

Consider the following data,which represent the number of miles that employees commute from home to work each day.There are two samples: one for males and one for females. Males: Females: Which of the following statements is true?

In drawing a box and whisker plot the length of the whiskers is 1.5(Q3-Q1).

The distribution of bankcard balances for customers is highly right-skewed with a mean of $1,100 and a standard deviation equal to $250.Based on this information,approximately 68 percent of the customers will have bank balances between $850 and $1,350.

Consider the following sample data: For these data the sample mean is: