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MathsMediumMCQ2023 ยท 10 Apr Shift 2

Q70.Let ๐œ‡ be the mean and ๐œŽ be the standard deviation of the distribution ๐‘‹๐‘– 0 1 2 3 4 5 ๐‘“๐‘– ๐‘˜+ 2 2๐‘˜ ๐‘˜2 - 1 ๐‘˜2 - 1 ๐‘˜2 + 1 ๐‘˜- 3 where ๐›ด๐‘“๐‘–= 62. If ๐‘ฅ denotes the greatest integer โ‰ค๐‘ฅ, then๐œ‡2 + ๐œŽ2 is equal to (1) 9 (2) 8 (3) 7 (4) 6

What This Question Tests

This question tests the ability to calculate the mean and standard deviation for a discrete frequency distribution, involving an unknown constant 'k' which needs to be determined first.

Concepts Tested

MeanVarianceStandard deviationDiscrete probability distribution

Formulas Used

Mean (ฮผ) = ฮฃ(Xi * fi) / ฮฃfi

Variance (ฯƒ^2) = (ฮฃ(Xi^2 * fi) / ฮฃfi) - ฮผ^2

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