Question

Assume that x has a normal distribution with the specified mean and standard deviation.

Find the indicated probability. (Enter a number. Round your answer to four decimal places.) μ = 20; σ = 4.4

P(x ≥ 30) =

Answer 1

Solution :

Given that ,

mean = = 20

standard deviation = = 4.4

P(x 30 ) = 1 - P(x   30 )

= 1 - P[(x - ) / ( 30 - 20 ) / 4.4 ]

= 1 -  P(z 2.27 )   

  Using z table,

= 1 - 0.9884

= 0.0116

Probability = 0.0116