Question

1. Use a table of standard normal curve areas to find the following:

a. The area to the left of z = 1.88
b. The area to the right of z = 1.42
c. The area to the left of z = −0.39
d. The area to the right of z = −0.46
e. The area between z = −1.22 and z = −0.5

Answer 1

a) 0.969

b) 0.0778

c) 0.348

d) 0.677

e) 0.1973

Explanation:

In the table of standard normal curve areas the area to the left of the z score represents the probability less than the z score. while, the area to the right of the z score represents the probability greater than the z score

a) The area to the left of z = 1.88

or

P(z < 1.88 ) = 0.969 [From table of standard normal curve areas]

b. The area to the right of z = 1.42

or

P(z > 1.42 ) = 0.0778 [From table of standard normal curve areas]

c. The area to the left of z = - 0.39

or

P(z < - 0.39 ) = 0.348 [From table of standard normal curve areas]

d. The area to the right of z = −0.46

or

P(z > -0.46 ) = 0.677 [From table of standard normal curve areas]

e. The area between z = −1.22 and z = −0.5

or

⇒ P(z < -0.5 ) - P(z < -1.22 )

or

⇒ 0.3085375 - 0.1112324 [From table of standard normal curve areas]

= 0.1973