Lesson 4: Measures and Visualization of Variability

Question 1

Tail is on the left side

Answer 1

Negatively skewed

Question 2

detailed version of range

Answer 2

quartiles

Question 3

How to get the median?

Answer 3

sort the data from highest to lowest or vice versa

=MEDIAN (dataset)

Question 4

Steps to create a boxplot

Answer 4

1. highlight the range (sorted from LH or HL
2. insert - box and whisker
3. Add label

Question 5

Tells us whether there is an outlier or none

Answer 5

Box plot

Question 6

Relatively symmetric (description, boxplot)

Answer 6

• median coincides with the mean
• the boxplot is partitioned equally
• skew = certain value

Question 7

Positively skewed (description, boxplot)

Answer 7

• skew to the right
• mean is greater than the median
• the box plot is partioned with the upper area bigger than the lower area
• many outliers are extending towards bigger value

Question 8

Negatively skewed (description, boxplot)

Answer 8

• skewed to the left
• median is greater than the mean
• the boxplot is partitioned with the upper area lower than the lower area.
• many outliers are extending towards smaller value

Question 9

To determine if it is outlier or not, we use _____________.

Answer 9

Interquartile range

Question 10

Formula of IQR

Answer 10

IQR = Q3 - Q1

Note: 1.5* IQR

Question 11

Get the new maximum value (use IQR)

Answer 11

Q3 + (1.5*IQR)
= New Max value (all data beyond the new max value is considered as an outlier)

Question 12

Get the new minimum value (IQR)

Answer 12

Q1 - (1.5* IQR)
= new minimum value ( all data below new min value is considered as an outliers)

Question 13

Divides the data points in four equal parts

Provides information on the spread of the data

Answer 13

Quartiles and Percentiles

Question 14

Causes of outliers

Answer 14

1. Data entry and measurement errors
2. Sampling problems
3. Natural Variation

Question 15

A term used in statistics to express how a score compares to other scores in the same set.

Answer 15

Percentile

Question 16

50th percentile is also known as …

Answer 16

Median

Question 17

A type of quantile which divides the number of data points into four parts, or quarters of more-or-less equal size.

Answer 17

Quartile

Question 18

The value at which 25% of the answer lie below that value, and 75% of the answers lie above that value.

Answer 18

25th Percentile

Question 19

The difference between the third and first quartiles

Answer 19

Interquartile range

Question 20

Extreme values that standout greatly from the overall pattern of values in a dataset or graph.

Answer 20

Outliers

Question 21

A chart that shows data from a five-number summary including one of the measures of central tendency

Answer 21

Box plot

Question 22

The value at which 50% of the answers lie above that value and 50% of the answers lie below that value

Answer 22

50th Percentile

Question 23

The value at which 25% of the answers lie above that value and 75% of the answers lie below that value.

Answer 23

75th Percentile

Question 24

Decisions And Outcomes:

Answer 24

Data-Analysis-Insights-Decision-Outcomes