Download Normalcdf (lower bound, upper bound, mean, SD)

Unit 3 WS 5 Normal Area with a Calculator (zscore)
Attempt to solve this problem:
On average it takes you 20 minutes to get to school with a standard deviation of 5. What percent of the
time will it take you between 19 and 24 minutes?
The empirical rule can only be used if the values have a z-score of -3, -2, -1, 0, 1, 2, 3. Those are the only
pre-set percentages. If the z-score do not come out as whole numbers - we use our calculator!
Normalcdf (lower bound, upper bound, mean, SD)
Notes:
*normal cdf can be found by pressing:________________________
*comma button is __________________________
* helps to sketch the picture and the bounds go from _________ to __________.
* for a greater than problem use ____________________ as the upper bound
*for a less than problem use ________________________ as the lower bound
*If using z – scores the mean is always ___________ and the SD is always ______
*calc will give you the decimal ________________ to get the percent.
* newer calcs it looks like this. Fill it in and hit past.
Lower:
Upper:
µ:
ơ:
Unit 3 WS 5 Normal Area with a Calculator (zscore)
First we are going to practice with z scores only. So mean will be _________ and SD will be _______.
Draw a quick sketch, then find the percentage on the calculator.
1. Between -2.3 and 2
2. To the right of -0.56
3. To the left of 2.78
4. To the left of -1.6 and to the right of 2.4
Sometimes the question is phrased as a probability. Like “What is the probability a person will be 60
inches or taller?” The process is the same, the notation is just a little different.
5. P(z>1.45)
6. P( 1.7 < z < 2.4)
7. P(z<-2.38)
8. P( 1<z<1.8)
Unit 3 WS 5 Normal Area with a Calculator (zscore)
Student practice: Draw a sketch and find the percentages on your calculator.
1. Between -.27 and – 1.94
2. P(.79 < Z < 1.24)
6. Between -1.22 and .09
7. P( -2.32 < Z < 1.03)
3. To the left of -.84
8. To the right of -1.34
4. P( Z > -1.73)
9. P( Z < 2.96)
5. To the left of -2.22 and to the right of 2.37
10. To the left of 1.34
Unit 3 WS 5 Normal Area with a Calculator (zscore)
11. P(-.67< Z < 1.51)
17. P ( -1.04 > Z )
12. To the right of 1.29
18. Between -1.57 and -.37
13. Between 1.94 and 1.09
19. P( -1.52 < Z < 1.82)
14. The top part of 1.17
20. The bottom part of – .88
15. The middle of 1.33 and .76
21. The middle of -0.84 and 1.94
16. P( -2.66 < Z < 0.77)
22. P( Z > 1.97)