1. Which of the following statements are true? (could be more than one)
A. a single observational study is efficient at identifying and controlling for lurking variables
B. assuming a large population in simple random sampling each individual in the population has the same probability to be selected
C. a survey is a type of observational study.
D. If an explanatory variable and a response variable are correlated, then it can safely be assumed that the explanatory variable causes the response variable.
E. Changes in the response variable can either explain or cause changes in the explanatory variable.
2. Assume X is binomially distributed with n=4 and p=0.8. Calculate P (X<=1)
3. Assume X is binomially distrbuted with n=20 p=0.4 Calculate P (X=7)
4. Suppose X and Y are independent random variables with meanX= 0 varianceX=10 Y= -9 varianceY= 9
W=-2X-4Y. What is the mean and variance of W
5. Let C and D be two events in sample space with P (C)=0.12 P(D)=0.36 P (C&D)=0.03 Determine the conditional probability P(C|D).
6. Can you please have 2 examples each for the experimental and observational study?