A two-way frequency table, or joint frequency table, can be used to summarize bivariate categorical data. It is a data display that shows how many data values fit into multiple categories.
The two-way frequency table displays the number of people at Chili Fest with which kind of chili they bought and whether they added extra spice or not.
Added spice | Did not add spice | Total | |
---|---|---|---|
Meat | 331 | 401 | 732 |
Vegetarian | 125 | 43 | 168 |
Total | 456 | 444 |
Describe the group of people which has exactly 401 people in it.
Identify whether the number of people who chose vegetarian chili is a marginal or joint frequency and state its value.
Calculate the total number of people who ate chili at Chili Fest.
A scientist recorded some data on the flowering pattern and type of soil for a variety of coreopsis plants:
The data can be organized into a joint frequency table:
Flowered | Did not flower | Total | |
---|---|---|---|
Peat soil | |||
Sandy soil | |||
Total |
Complete the table based on the given information about coreopsis plants.
Keshawn said because there were a total of 1000 plants observed and 30 plants that were planted in sandy soil did not flower, this means 1000-30=970 were planted in peat soil and did flower. Identify and correct his error.