Explanation:

- Let S = sum of values = x1 + x2 + ... + x?

- The sum of deviations from 100 is: S – 100n = -20

- The sum of deviations from 92 is: S – 92n = 140

- To find n, subtract the first from the second:

    (S – 92n) – (S – 100n) = 140 – (-20)

    8n = 160 ? n = 20

- S = 100n – 20 = 100×20 – 20 = 1980

- If algebraic sum of deviations from y is 180:

    S – yn = 180

    1980 – 20y = 180 ? 20y = 1800 ? y = 90

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Option 1: 80

Option 2: 85

Option 3: 90

Option 4: 95

Option 3 (90) is correct.