Goodness of fit test
Task
A toy company sells trading cards with animal prints. The company claims that 25% of the cards are reptiles, 60% mammals, and 15% are birds.
Suppose a random sample of 100 cards has 20 reptiles, 55 mammals, and 25 birds.
Is this consistent with the company claim? Use a 0.05 level of significance.
Instructions
| 1. | Open the tab Statistics. |
| 2. | Choose the Goodness of Fit Test as your preferred test from the drop-down list. |
| 3. | Select a number of 3 rows, because there are 3 different categories, the mammals, the reptiles and the birds. |
| 4. | In the column Observed Count type in the observed numbers of cards, 20 reptiles, 55 mammals and 25 birds. |
| 5. | In the column Expected Count type in the claimed numbers of cards, 25 reptiles, 60 mammals and 15 birds. |
| 6. | Check the Result section to interpret the relevant parameter values for your statistical test. |
| Note: GeoGebra automatically calculates the corresponding probability based on a normal distribution (P), the degrees of freedom (df) and the chi-square test statistic (X2). |