Chapter 8: Descriptive Statistics

Given the following numbers, which is the mode? 1,6,1,5,2,2,1

1

The variance is 100, the standard deviation is ___ .

10

If the lowest value in a dataset is 25 and the highest value is 125, the range is ___.

100

The standard deviation is 5, the variance is ___ .

25

Given the following numbers, which is the median? 7,1,16,6,5

6

A product quality report rates quality on a scale of 1 to 7. Only one of seven boxes can be checked. This is an example of a continuous variable

FALSE

As the standard deviation gets larger, the variance gets smaller.

FALSE

As the standard deviation gets larger, the variation in the data gets smaller.

FALSE

The closer are the observations in a distribution, the larger is the standard deviation.

FALSE

The greater is the variation of data in a dataset, the lower will be the standard deviation.

FALSE

The mean and median can never be the same.

FALSE

The range is a measure of variation that takes into consideration all values in a dataset.

FALSE

The standard deviation is a measure or "statistic" that is used to quantify the variation in a data set and is represented by the letter "X".

FALSE

Two statistics can be used to summarize a distribution. They include the mean and average.

FALSE

A sample of parts is collected from a production process. The parts are classified as either good or bad. If the variable is "part quality" the variable is discrete.

TRUE

If the highest number in a range is 40 and lowest is 22, an estimate of the standard deviation is 3.

TRUE

If the standard deviation of one data set is greater than the standard deviation of another, the values in the data set of the first data set are more widely dispersed than the values in the second.

TRUE

It is possible for the mean, median and mode to be the same.

TRUE

The benefit associated with using the standard deviation over the range as a measure of variation is that the standard deviation is a statistical measure that takes into consideration every item in the data set.

TRUE

The benefit of the standard deviation over the range is that it uses every data item in the dataset to measure variation not just the lowest and highest values.

TRUE

The goal in an emergency department is to register and process all patients quickly. This suggests that if patient registration and processing times were recorded, the standard deviation of this data set should be small as this could reduce the chances of a bottleneck.

TRUE

The mean is a measure of central tendency and as such represents one way to identify the central point in a distribution.

TRUE

The range can be used as a measure of variation.

TRUE

The range of one data set is from 20 to 80. A quick estimate of the standard deviation is 10.

TRUE

The standard deviation represents the extent of the spread of the data in a dataset

TRUE

To improve scheduling patients through an MRI, the standard deviation for the length of time it takes to complete the process for specific scans should be a small as possible.

TRUE

Variation in the time it takes to process units through an assembly operation in a manufacturing plant can lead to bottlenecks as some units may take longer than expected.

TRUE

When the standard deviation is larger in dataset A than it is in dataset B, this suggests a wider dispersion of the data from the mean in dataset A.

TRUE

The length of time to serve a customer at a bank's teller window would be considered a _________ variable.

continuous

The two types of variables commonly encountered in Six Sigma are ________ and _________.

continuous, discrete