Ap Statistics Worksheet (Page 2 of 2) in pdf

Ap Statistics Worksheet Page 2

Name: __________________________________________

Date: ______________

To use the calculator to find the area under a normal curve:

1) If not given the z-score, then use the z-score formula to standardize the value.

2) Go to 2

-VARS-#2 normalcdf

3) You can input either a z-scores, or ,

a. If you use z-scores: normalcdf (lower z, upper z)

b. If you use raw data (x, , ):

Normalcdf (lower bound, upper bound, , )

 If not given a lower bound, you can use -

by typing -1e99. You input

the letter ‘e’ by pressing the 2

key, then the comma key.

 If not given an upper bound, you can use +

by typing 1e99.

 You can report the value as a percent or as a decimal.

To use the calculator to draw a normal curve and see the shading underneath:

1) Make sure STAT PLOTS (2

, y=) is OFF, and no graphs exist (y=) .

2) Set window to view correctly: xmin= -3, xmax = 3, xscale = 1, ymin = -.1,

ymax=.5, yscale = 1, res=1.

3) Go to 2

-VARS DRAW #1ShadeNorm(lower z, upper z)

4) You will need to clear drawing each time, or the next entry may give a

correct answer for area under curve, but an incorrect drawing.

a. Press 2

PGM #1ClrDraw.

To find a data value that represents a certain percentile, when given , :

1) Go to 2

-VARS-#3 invNorm (percentile as a decimal, , )

To find the z-score associated with a percentile under a standardized normal

curve meaning N(0,1):

2) Simply got to 2

-VARS-#3 invNorm(percentile as a decimal

Note: You do not have to close ( )’s.

Example: To find the z-score associated with 75

percentile, or the value of Q3,

press invNorm(.75 = .67. Therefore, z=.67 at the 75

percentile.

Ap Statistics Worksheet Page 2