A dihybrid cross is expected to give offspring in the ratio 9 : 3 : 3 : 1. Among 240 offspring the counts shown are observed. Compute the chi-square goodness-of-fit statistic χ² for H₀: the ratio is 9 : 3 : 3 : 1.
Chi-square tests worksheet with answers
A sweet manufacturer claims the colour proportions shown in the table. A random sample of 80 sweets gives the observed counts. Compute the chi-square goodness-of-fit statistic χ² for H₀: the claimed proportions are correct.
The contingency table shows observed counts. For a chi-square test of independence, find the expected count E for the cell “urban, medium”.
The contingency table shows observed counts. Compute the chi-square statistic χ² for the test of independence between the row and column variables. Do not use a continuity correction.
A chi-square test of independence is carried out on a contingency table with 2 rows and 5 columns (not counting the totals). How many degrees of freedom df does the test have?
A chi-square goodness-of-fit test compares observed counts in 10 categories with fully specified expected proportions (no parameters are estimated from the data). How many degrees of freedom df does the test have?
Answer key
- 1. χ² = 82.61
- 2. χ² = 0.8167
- 3. E = 29.72
- 4. χ² = 11.66
- 5. df = 4
- 6. df = 9
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