Two-Way Frequency Tables / Alg 1

Concept Notes Page - Two-way frequency tables

1)  The _marginal__ frequencies are the sums of each row and column in a two-way table.

2)  The points of intersection between the two categories are called _joint_ frequencies.

3)  The joint relative frequencies should total _1_.

4)  By convention, the joint and marginal relative frequencies are calculated as _decimals instead of percentages.

Try these

1)  A public opinion survey explored the relationship between age and support for increasing the minimum wage. The results are found in the following two-way frequency table.

For / Against / No Opinion / TOTAL
Ages 21-40 / 25 / 20 / 5 / 50
Ages 41-60 / 30 / 30 / 15 / 75
Over 60 / 50 / 20 / 5 / 75
TOTAL / 105 / 70 / 25 / 200

1.  Fill in the missing data to the table.

See above

2.  Create a two-way frequency table that summarizes the data from the table. Include marginal frequencies and interpret the joint frequencies of the table.

For / Against / No Opinion / TOTAL
Ages 21-40 / .125 / .1 / .025 / .25
Ages 41-60 / .15 / .15 / .075 / .375
Over 60 / .25 / .1 / .025 / .375
TOTAL / .525 / .35 / .125 / 1

3.  Out of the people that have no opinion, what percentage is over 60 years old?

.2 or 20%

4.  What percentage of people is for increasing minimum wage?

.525 or 52.5%

5.  How many people over 60 are against increasing the minimum wage?

.25 or 25%

6.  For ages 21-60 how many were not against increasing the minimum wage?

.6 or 60%

7.  What percent of people over 60 are against or have no opinion?

33.3%

1

Problems from http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&ved=0CFUQFjAJ&url=http%3A%2F%2Fmrsstephanieandersonsclassroom.weebly.com%2Fuploads%2F1%2F8%2F5%2F7%2F18572420%2Flesson_5_-_two-way_frequency_tables.docx&ei=ygE3U4OvD4nNsQS5sIGQBQ&usg=AFQjCNG0wj4mmOGnxNfhvroeUAf_4zJ43g&sig2=rb0nmqO6kN-FNvV_6bcgyA&bvm=bv.63808443,d.dmQ