Warm Up – Test Review

Marginal and Conditional

Researchers looking at the relationship between the type of college attended (public or private) and achievement gather the following data on 3265 people who graduated from college in the same year.

The variable “management level” describes their job description 20 years after graduating from college.

a. Calculate the marginal distribution of management level in percents.

b. Find the conditional distribution of management level for each college type, in percents.

c. Sketch the data from part (b) in a segmented bar graph and in a side-by-side bar graph.

a. Calculate the marginal distribution of management level in percents.

 

1769 1496

1821756

1327

3265

%6.403265

1327

%8.533265

1756

%6.53265

182

Low

Medium

High

b. Find the conditional distribution of management level for each college type, in percents.

 

1769 1496

1821756

1327

3265

Public Private

High =4.2 % = 7.2 %

Medium = 54.4 %

= 53.1 %

Low = 41.4 % = 39.8 %

c. Sketch the data from part (b) in a segmented bar graph and in a side-by-side bar graph.

Public Private

High 4.2 % 7.2 %

Medium 54.4 % 53.1 %

Low 41.4 % 39.8 %

c. Sketch the data from part (b) in a segmented bar graph and in a side-by-side bar graph.

Public Private

High 4.2 % 7.2 %

Medium 54.4 % 53.1 %

Low 41.4 % 39.8 %

20

40

60

80

100

10

20

30

40

50

60

Public Private

Low

Med

High

Med

Low

High

%

Low

Pub

lic

Pri

vate

Pub

lic

Pri

vate

Medium

Pub

lic

Pri

vate

High

Below is a graph showing the total number of Oscar nominations for the four films that had PG or PG-13 ratings. What’s wrong with the way the information is presented in this graph?

Using similar figures to compare heights exaggerates the differences between frequencies since people (wrongly) tend to compare areas.

Graph the following:

Class Freq.20-40 3540-60 2760-100 20100-200 10200 – 800 28