Find the following percentiles for the standard normal distribution. Interpolate where appropriate. a.? ?91st b.?? th c.? ?75th d.? ?25th e.?? th

Answer : Step 1 of 5 : The claim is to find the percentiles for the standard normal distribution. a) We have to find the z value for 91 st percentile P(Z z ) = 0.91 We have to check standard normal table for the value 0.91 91 lies in 1.3 row and 4th column Therefore, z = 1.34 Hence, P(Z 1.34 ) = 0.91 Step 2 of 5 : b) We have to find the z value for 9th percentile P(Z z ) = 0.09 We have to check standard normal table for the value 0.09 09 lies in -1.3 row and 4th column Therefore, z = -1.34 Hence, P(Z -1.34 ) = 0.09 Step 3 of 5 : c) We have to find the z value for 75th percentile P(Z z ) = 0.75 We have to check standard normal table for the value 0.75 0.75 lies in 0.6 row and 7th column and 0.6th row and 7th column (0.67+0.67) Therefore, z = 2 = 0.675 Hence, P(Z 0.675 ) = 0.75