Question

Using your calculator, find the proportion of observations from a standard normal distribution that satisfies the following statement. Sketch the normal curve and shade the area under the curve that is the answer to the question: Z < –1.5.

Answer 1

Look at your table for a Z value of 1.55. The numbers on the far left column are your z values. See the 1.5 row, then move over to the 0.05 column to make it 1.55.
You'll see 0.9394.
That's the area under the normal curve from 1.55 to negative infinity.
But you wanted the area under the curve greater than 1.55.
Take 1-0.9394=0.0606.
You subtract from 1 because you know that the area under the whole curve is 1, so it gives you the area you need.