Question

the average height is 100 , with a variance of 1.21. The probability that you will randomly encounter a person taller than 101.38 and shorter than 100.00is closest to:

		0.1056
		0.3944
		0.6056
		0.7888
		0.8944

Answer 1

Solution :

Given that ,

mean = = 100

2 =1.21

standard deviation = =1.1

P(100< x <101.38) = P[ (100-100) /1.1 )< (x - ) / <(101.38-100) /1.1 ]

= P(0< Z <1.25 )

= P(Z < 1.25) - P(Z < 0)

Using z table   

= 0.8944 -0.5000

probability= 0.3944