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Course Documents
Chapter 1 - Intro
Chapter 2 - Methods for Describing Sets of Data
Chapter 3 - Probability
Chapter 4 - Discrete Random Variables
Chapter 5 - Normal Random Variables
Chapter 6 - Sampling Distributions
Chapter 7 - Confidence Intervals
Chapter 8 - Tests of Hypothesis: One Sample
Chapter 9 - Confidence Intervals and Hypothesis Tests: Two Samples
Sample Exam I: Chapters 1 & 2
Sample Exam II: Chapters 3 & 4
Sample Exam III: Chapters 5 & 6
Sample Exam IV: Chapters 7 & 8
Prof. I am having same issue on #40 ch 3 Probability
It says find 10C2 on calculator answer is 45. But if I attempt to work it out this is what I get:
1st try: (10/2)= 10!/2! Then I get 10*9*8*7*6*5*4*3*2!/2! I cancel both 2!'s so am left with 10*9*8*7*6*5*4*3=1,814,400. Can you explain please. I know I got right answer using calculator but this simplifying is driving me crazy! Not sure what am doing wrong.
Posted to on Tuesday, February 11, 2014 Replies: 1
Hi Natalia,
You need to be a precise record keeper if you are going to perform the calculation by hand. In this case, you did not fill in the formula properly before starting the work. You left out your 8!. Use your formula card or commit the formula to memory.
10C2 = 10!/(2!*8!) = 10*9*8!/(2*1*8!) = 10*9/2 = 45
Sincerely,
Professor McGuckian
STATS1
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