Understanding Measures of Dispersion

What is the first step in determining if data vary?

• Finding the mode

• Summarizing the data

• Calculating the median

• Calculating the Z-score

In the Rotten Tomatoes example, what is the range of scores?

• 0 to 100

• 60 to 100

• 80 to 100

• 59 to 100

Which measure of dispersion is calculated on the way to finding the Standard Deviation?

• Range

• Variance

• Mean

• Z-score

What does a Variance of 0 indicate about a dataset?

• All scores are different

• All scores are the same

• Scores are widely spread

• Scores are normally distributed

In a normal distribution, what percentage of scores lie within one standard deviation of the mean?

• 95%

• 99%

• 50%

• 68%

If a dataset has a mean of 42 and a standard deviation of 12, what is the score at two standard deviations above the mean?

• 66

• 54

• 78

• 90

What does a higher Standard Deviation indicate about a dataset?

• Scores are normally distributed

• Scores are all the same

• Scores are more spread out

• Scores are closer to the mean

In the movie rating example, what does a lower standard deviation suggest about the ratings?

• Ratings are lower

• Ratings are more varied

• Ratings are higher

• Ratings are more consistent

When designing airplane seats, what does accommodating 95% of passengers involve?

• Using two standard deviations

• Using one standard deviation

• Using three standard deviations

• Using the mean size

What is the main purpose of measures of dispersion?

• To find the mean

• To determine the mode

• To display the range and variability of scores

• To calculate the median