Question

Find the area under the standard normal curve for the following:

(A) P(z > 2.06)
(B) P(0 < z < 0.18)
(C) P(-1.31 < z < 1.09)



@ap statistics

Answer 1

Yeah, you need a calculator for this. You'll want to use the normalcdf on a ti calculator

Answer 2

I have been using the one I have TI-30XA.
I am looking it up in my book to see if I can figure it out. But I do not get what to start with. I guess I will figure it out. If you can help I would appreciate it. I am having a rough time with these.

Answer 3

So the probability like this is the area under the normal graph. So probability z > 2.06 means the area under the graph from z=2.06 to z=infinity. normalcdf(a,b) gives the area under the curve form z=a to z=b. So for problem A we want to do normalcdf(2.06,999999).

Answer 4

This is what I came up with:
(A)
P(z > 2.06)
2.06=0.4803
P(z> 2.06)=0.5000-0.4803=0.0197

(B)
P(0<z<0.18)
0.18=0.0714
P(0<z<0.18)=0.0714

(C)
P(-1.31<z<1.09)
-1.31=0.4049
1.09=0.3621
P(-1.31<z<1.09)=0.4049 - 0.3621=0.0428

Answer 5

For the last one you'll want to add them instead of subtracting. Draw a diagram to go with situation in order to help the operations

Answer 6

because the first part of the question is a negative, right?

Answer 7

so the last ones answer is 0.7670

Answer 8

Because the 0.4049 is area from -1.31 to 0 and 0,3621 is area from 0 to 1.09. You want area from -1.31 to 1.09 so you add

Answer 9

and yes

Answer 10

Thank you.

Answer 11

I usually draw a diagram like this to help me