Question

A population is normally distributed with μ=300 and σ=20.

A. Find the probability that a value randomly selected from this population will have a value greater than 345

B. Find the probability that a value randomly selected from this population will have a value less than 295

C. Find the probability that a value randomly selected from this population will have a value between 295 and 345

Click the icon to view the standard normal table.

A. P( x > 345)= ______________ (round to four decimal places as needed)

B. P( x< 295)= ________________ (Round to four decimal places as needed)

C. P( 295 < x < 345)= ____________ (round to four decimal places as needed)

Answer 1

µ = 300

sd = 20

a)

                                

                                 = P(Z > 2.25)

                                 = 1 - P(Z < 2.25)

                                 = 1 - 0.9878

                                 = 0.0122

b)

                               

                                = P(Z < -0.25)

                                = 0.4013

c)

                                             

                                              = P(-0.25 < Z < 2.25)

                                              = P(Z < 2.25) - P(Z < -0.25)

                                              = 0.9878 - 0.4013

                                              = 0.5865