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Consider the continuous random variable with probability density function
f(t) = 1 + t for – 1 ≤ t ≤ 0
= 1 – t for 0 ≤ t ≤ 5 1
The standard deviation of the random variable is
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- 1/√3
- 1/√6
- 1/3
- 1/6
Correct Option: B
Mean(t) ∞∫-1 t.f(t).dt = o∫-1(1 + t)dt 1∫ot(1 - t)dt 
Variance = ∞∫-∞(t - t)² f(t).dt
o∫-1 t² (1 + t)dt + 1∫o t²(1 - t)dt = 1/6
Stan dard deviation = √Variance =1/√6
