1.

The random variable X is normally distributed with a mean of 70 and a standard deviation of 10. What is the probability that X is between 72 and 84? (a) 0.683 (b) 0.954 (c) 0.271 (d) 0.340

Answer»

(d) 0.340 

µ = 70, σ = 10 

P(72 < X < 84) = P((72 - 70)/10 < Z < (84 - 70)/10)

= P(0.2 < Z < 1.4) 

= P(0 < Z < 1.4) – P(0 < Z < 0.2) 

= 0.4192 – 0.0793 

= 0.3399 

= 0.340



Discussion

No Comment Found

Related InterviewSolutions