- CFA Exams
- CFA Level I Exam
- Topic 1. Quantitative Methods
- Learning Module 8. Hypothesis Testing
- Subject 3. Test Statistic and Significance Level
CFA Practice Question
We want to test the claim that a steady diet of wolfsbane will cause an 18-year-old werewolf to lose EXACTLY 10 lbs. over 5 months. A random sample of 49 werewolf was taken, yielding an average weight loss over 5 months of 12.5 lbs with S = 7 lbs. Let alpha = .02. What is the calculated value suitable for testing the above hypothesis?
B. 7 x 2.5
C. 2.5
A. 12.5
B. 7 x 2.5
C. 2.5
Correct Answer: C
t(calculated) = (12.5-10)/(7/SQRT(49)) = 2.5
User Contributed Comments 9
User | Comment |
---|---|
isida | test statistic question: (sample statistic - null value) / standard error standard error = standard deviation / sqrt N |
Masterkang | Obviously, he read to many Harry Potter Books... |
achu | we know it's t-test because S sample sd, not population std dev. |
steved333 | Yes, but sample size is large, so it doesn't matter. T-stat is the same as Z in this case. |
poomie83 | Was alpha there as useless information? |
ybavly | @poomie83 yes |
johntan1979 | Agree with steved333. n>30, so Z. |
sgossett86 | the equation for variance is single bernoulli variable |
Shaan23 | You guys need to read the notes. One we dont know if this is normal or not. Population variance is unknown. Whenever population variance is unknown always jump to t-test. But remember t-test approaches the z test when n becomes big. |