CHAPTER 3 REVIEW

CENTRAL TENDENCY

100

Middle number in a data set

Median

200

I occur more frequently

Mode

300

What is the mode

2, 5, 6, 2, 5, 9, 5, 8, 2

2, 5

400

What is the median value

1, 6, 7, 8, 11, 12

7.5

500

Calculate the mean

2, 9, 4, 12, 5, 8

6.67

MEASURES OF VARIANCE

100

Name the symbol below

         x̄

  sample mean

200

What is variance 

a measure of dispersion, meaning it is a measure of how far a set of numbers is spread out from their average value.

300

Range of the data set

3.5, 8, 9.5, 12, 18, 45, 6, 7.0, 18

41.5

400

How does variance and standard deviation relates to the spread of data

standard deviation represents the "average" distance of data points from the mean, while variance represents the average squared distance from the mean, making standard deviation easier to interpret as it is in the same units as the original data; a larger variance or standard deviation signifies a wider spread of data points around the mean

500

Given that the number of entries in the data set is 5 and the ⅀(𝑥𝑖 − 𝑥̅)2 is 40. What is the variance and standard deviation?

Variance: 10

Standard Deviation: 3.16

BOX PLOTS

100

Another name for Q₃

Upper quartile

200

How do we calculate the IQR?

 Q3 - Q1

300

What percentage of data lies above the lower quartile?

 75%

400

Five Number Summary 

Minimum

Lower Quartile

Median

Upper Quartile

Maximum

500

Find the five number summary for the set below

3, 7, 8, 12, 3, 1, 10, 8, 5, 3, 15, 20

Minimum- 1

Lower Quartile- 3

Median- 7.5

Upper Quartile-11

Maximum- 20

TRIMMED MEAN

100

What is an outlier? 

an observation that lies an abnormal distance from other values in a random sample from a population

200

Identify the outlier(s)

15, 67, 4, 88, 23, 25, 12

4 and 88

300

If a data set consist of outliers which is best to use?

Arithmetic mean or trimmed mean

Trimmed mean

400

What does a trimmed mean do to a given data set

 removes a specified percentage of the highest and lowest values before calculating the mean, effectively reducing the influence of outliers and providing a more accurate representation of the central tendency when dealing with skewed data distributions.

500

Find 10% trimmed mean for the set below

3, 19, 10, 12, 8, 15, 88, 45, 20, 25

19.25