Exam 3: Descriptive Statistics

A box-and-whisker plot for last year's data is compared with a box-and-whisker plot for this year's data.The biggest change is that the median is moved from the left side of the box to the right side of the box.The other elements of the plot remained fairly constant.Based on this change, it can be concluded that ___________.

The hourly production of a plastic cup company is tracked over several months and is found to be normally distributed.Given a mean of 15,630 cups and a standard deviation of 251 cups, about what percent of all hours of production should produce between 15,379 and 15,881 cups?

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

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

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

A sample of 117 records of the selling price of homes from Feb 15 to Apr 30, 2018 was taken from the files maintained by the Albuquerque Board of Realtors.The following are summary statistics for the selling prices. From this we can conclude that,

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

After obtaining a large data set, a business analyst will first want to determine _________.

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 modal gain or (loss)was _____

The mean life of a particular brand of light bulb is 1000 hours and the standard deviation is 50 hours.Tests show that the life of the bulb is approximately normally distributed.It can be concluded that approximately 68% of the bulbs will last between ___.

A given set of normally distributed data values has a mean of 75, a standard deviation of 8.50 and a z-score of 2.45.What is the approximate value of x₁?

Skewness indicates that a data distribution is symmetrical or asymmetrical.

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?

The following ten data values are provided: The value of Q₁ is _____

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 95% of the batteries will last between ___.

Data sets with more than one mode are referred to as bimodal

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

By comparing the mean and median of a variable in a large data set, a business analyst can assess the variability within the values of that variable.

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

Stock A has a coefficient of variation of 30% and stock B has a coefficient of variation of 35%.Based on this measure of risk, which stock would be considered riskier?