Question

Please Help Me!!

The standard normal curve shown below is a probability density curve for a continuous random variable. This means that the area underneath the entire curve is 1. What is the area of the shaded region between the two z-scores indicated in the diagram?

Answer 1

You can use the z-table at the following link to find the cumulative probabilities for the two given z-scores.
http://lilt.ilstu.edu/dasacke/eco148/ztable.htm
When you have the two values of cumulative probability, subtract the smaller value from the larger value to find the solution.

Answer 2

I don't know how to use that D:

Answer 3

Plus I don't see my sec on value I'll need

Answer 4

Firstly, to find the cumulative probability for z = -1.3, go to the left hand column headed z and go down to -1.3. Then move right to the next column (headed .00) to find the cumulative probability for z = -1.3. What value do you get?

Answer 5

.0968

Answer 6

Good work! That is correct. Now can you find the cumulative probability for z = 0.75?

Answer 7

Subtract that .0968 from 0.75?

Answer 8

No. You need to use the z-table again. Go to the left hand column headed z and go down to the value 0.7. Then move to the right to the column headed .05 to find the cumulative probability for z = 0.75. What value do you get?

Answer 9

.7734

Answer 10

Good work again! Now subtract 0.0968 from 0.7734.

Answer 11

-0.6766

Answer 12

Thanks:D

Answer 13

Remove the negative sign, and you have the correct answer.

Answer 14

You're welcome :)