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22S:008 Exam 2, Part I, April 9, 1999 Name:_______________________________
Please circle one. Section: 11:30, 12:30, or 2:30
Please enter all of your answers on these exam pages. There are 19 questions. The Defective Question Report
Formula sheet and Normal tables will be handed out separately.
1. (2 pts) In a designed experiment, a sham or fake treatment disguised as a real treatment it is called a placebo.
A) True B) False
2. (2 pts) An ecological variable is a variable that plausibly explains a relationship between two other
variables.
A) True B) False
3. (3 pts) Suppose y is a response variable of annual salary, x is a continuous predictor variable of years of
experience, and z is a binary indicator variable indicating gender (z=1 means female, z=0 means male).
Consider the regression model with fitted equation: . What coefficient or combination of
coefficients represents the predicted annual salary for a male with one year of experience?
A) b0
B) b1
C) b2
D) b0+b1
E) b0+b2
4. (3 pts) In a taste test of three pizza recipes, several different tasters evaluated each of the three recipes. This is
an example of
A) replication
B) blinding
C) placebo
D) randomization
E) control
5. (2 pts.) In the preceding question there are _____ factor(s) each with _____ levels.
6. (3 pts) A professor asked his class to guess his age in years. Half the class were given the hint that his oldest
child was 35 years old. The other half received no hint. The half that received no hint is called the
A) blind group
B) control group
C) factor group
D) treatment group
E) None of the above.
y
ˆb0b1xb
2z
++=
