If X has a Normal distribution of N400 225 a P 175 X 225So

If X has a Normal distribution of N(400, 225)

a) P ( 175 < X< 225)

Solution

If X has a Normal distribution of N(400, 225)

a) P ( 175 < X< 225)

z value of 175, z=( 175-400)/225 = -1

z value of 225, z=( 225-400)/225 = -0.78

P ( 175 < X< 225)

= P ( -1 < z < -0.78)

P( z < -0.78) – P( z < -1)

= 0.2177 - 0.1587

= 0.0590