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AP EAMCET20228 Jul 2022Morning ShiftMathematicsProbabilityActual

The probability that A wakes up before the alarm rings is 0.4 . Then, the mean and variance of the number of times A wakes up before the alarm rings, in the next 7 days respectively are:

Options

  1. A0.4,0.6
  2. B2.8,0.6
  3. C2.8,1.68
  4. D7,0.6

Correct answer

C. 2.8,1.68

Step-by-step solution

We are given that x=7 aligned & p =0.7, q =1-0.4=0.6 & Now mean =x p =7 0.4=2.8 & Variance =x p q=2.8 0.6=1.68 aligned

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