1. **Problem Statement:** Compute all the remaining possible class frequencies from the given data: $\alpha = 50$, $\beta = 70$, $(AB) = 20$, and total $n = 100$. 2. **Understanding the problem:** We are given partial class frequencies and total sample size. We need to find the frequencies of the other classes. 3. **Notation and formula:** Assuming the classes are $\alpha$, $\beta$, $AB$, and the remaining class $O$ (others), the sum of all class frequencies must equal total $n$: $$\alpha + \beta + (AB) + O = n$$ 4. **Substitute known values:** $$50 + 70 + 20 + O = 100$$ 5. **Simplify:** $$140 + 20 + O = 100$$ $$160 + O = 100$$ 6. **Isolate $O$:** $$O = 100 - 160$$ $$O = -60$$ 7. **Interpretation:** A negative frequency is not possible, so there might be an inconsistency in the data or assumptions. 8. **Check if $AB$ is part of $\alpha$ and $\beta$ or separate:** If $AB$ overlaps with $\alpha$ and $\beta$, the calculation changes. Without further info, we cannot find other frequencies. **Final answer:** With given data and assumptions, the remaining class frequency $O = -60$, which is impossible. More information or clarification is needed to solve this correctly.