A dihybrid cross is expected to give offspring in the ratio 9 : 3 : 3 : 1. Among 400 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 100 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 “day shift, major”.
The contingency table shows observed counts. For a chi-square test of independence, find the expected count E for the cell “urban, high”.
A chi-square goodness-of-fit test compares observed counts in 5 categories with fully specified expected proportions (no parameters are estimated from the data). How many degrees of freedom df does the test have?
The table shows observed counts. Test at α = 0.05 whether the two variables are independent (no continuity correction). Compute the test statistic χ², then compare it with the critical value from the table.
Answer key
- 1. χ² = 8.124
- 2. χ² = 1.013
- 3. E = 27.26
- 4. E = 30.46
- 5. df = 4
- 6. χ² = 2.071
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