A dihybrid cross is expected to give offspring in the ratio 9 : 3 : 3 : 1. Among 192 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 60 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. For a chi-square test of independence, find the expected count E for the cell “rural, medium”.
A chi-square test of independence is carried out on a contingency table with 2 rows and 11 columns (not counting the totals). Using the table, find the critical value χ²crit at significance level α = 0.05.
A chi-square goodness-of-fit test checks whether counts in 7 categories follow a Poisson distribution whose mean is estimated from the same data. How many degrees of freedom df does the test have?
Answer key
- 1. χ² = 53.11
- 2. χ² = 12.67
- 3. E = 14.62
- 4. E = 32.87
- 5. χ²crit = 18.31
- 6. df = 5
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