Measures of Central Tendency and Spread

The video tutorial explains how to describe the center and spread of numerical data using median, mean, and interquartile range (IQR). It covers methods to find the median in odd and even datasets, compares mean and median in different distributions, and introduces quartiles. The tutorial also explains how to calculate quartiles and use a five-number summary to summarize data. Finally, it discusses the range and IQR, emphasizing their importance in understanding data spread, especially in skewed distributions.

What are the two measures used to describe the center and spread of numerical data?

• Mode and Variance

• Standard Deviation and Mean

• Median and Interquartile Range

• Mean and Range

How is the median different from the mean?

• Median is a calculation, mean is a location

• Median is always larger than the mean

• Median is a location, mean is a calculation

• Median is used for categorical data

How do you find the median in a dataset with an odd number of values?

• Average the two middle values

• Select the middle value

• Select the largest value

• Select the smallest value

In a symmetric distribution, how do the mean and median compare?

• Mean is always larger

• Median is always larger

• They are approximately the same

• They are unrelated

What happens to the mean in a skewed left distribution?

• Mean is larger than the median

• Mean is smaller than the median

• Mean is unaffected

• Mean equals the median

What is the purpose of quartiles in data analysis?

• To calculate the range

• To find the average

• To divide data into quarters

• To divide data into halves

How is the first quartile (Q1) determined?

• By finding the median of the upper half of the dataset

• By averaging the maximum and minimum values

• By finding the median of the lower half of the dataset

• By finding the median of the entire dataset

What does the third quartile (Q3) represent?

• The median of the entire dataset

• The median of the lower half of the dataset

• The average of all data points

• The median of the upper half of the dataset

What are the components of a five-number summary?

• Minimum, Q1, Median, Q3, Maximum

• Mean, Median, Mode, Range, Variance

• Minimum, Maximum, Mean, Median, Mode

• Q1, Q2, Q3, Q4, Maximum

Why is range not a reliable measure of spread in skewed distributions?

• It only considers the middle 50% of data

• It is influenced by outliers

• It is always larger than the interquartile range

• It is not influenced by outliers