Official 2020 AP Stats Exam College Board Lesson #7 Normal Distribution Calculations 4_14_2020

Hi All!



That was a nice lesson from Brendan Murphy!  Here are my take-aways and teacher comments:



Brief Reminders:

• Lessons are here: https://www.youtube.com/watch?v=8md9vY_QL6w&list=PLoGgviqq4845u-QDW3bikMhC4uQsuYDpy&index=15

• Lessons: April 6-10: Units 6-7 taught first because many schools either didn’t get to these entirely or at all (we did get through most of this); April 13-May 1: Units 1-5
• AP Stats Exam Friday May 22 from 2-2:45 EST
• All resources available at Statsmedic.com/youtube
• If you need a device take the Exam go to cb.org/tech

Last night’s homework:

• We use SOCS or CUSS and BS to describe a distribution and USE CONTEXT at least one time within

Example #1--2002 AP Exam Multiple Choice #10:

• 4000/10000 gives the .4 (40%)
• We use the 2^nd àVARS: 2: Normalcdf(lower limit, upper limit, 0,1) to get the proportion

Example #2—2007 AP Exam Multiple Choice #3:

• You can use the  Normalcdf(-9999, -1, 0,1) = 0.1586 and Normalcdf(-9999, 1, 0,1) = 0.0.8413 to get the percentile values he displays on line 3
• 2^nd àVARS: 3: InvNorm(.67, 0,1) = 0.44 (the z-score he reports)
• Clever technique to answer the question when mean is unknown by using a proportion 😊

Example #3 “Shirt/neck size” – 2003 AP Exam FRQ #3

• Part a) You can add the  Normalcdf(-9999, -2.42, 0,1) = 0.007 and Normalcdf(3.285, 9999, 0,1) = 0.00051 to get the 0.008 result that he got (we use the actual z-scores in our studies)
• Part b) is just a basic sketch of the curve for the requested values (again though, we actually compute and use the z-scores as in the bullet above)
• Nice reminder that it’s important to make sure that you answer all of the questions in requested!

Example #4 “Trains” – 2004 AP Exam FRQ #3

• Part a) You can use the  Normalcdf(0.78, 9999, 0,1) = 0.22 (we use the actual z-scores in our studies)  
• Part b) Nice reminder that if the probability result is not less than 5%, it is not considered unusual (we wouldn’t be surprised).  Connect this to a significance test where if the p-value is not less than the alpha level 0.05 we DO NOT REJEST the Null Hypothesis 😊

Example #5– 2011 AP Exam FRQ #1

• A nice question on computing and interpreting a z-score 😊

If you can, do the homework on bivariate data and lsrl (or watch the recoding at you leisure) and follow along as we learn.



As always please email me with questions, comments, thoughts.



Take care!