ECON 230 Test 1
Name:
Section (Circle one): 9:25 10:50
You will be graded based on the answers that you write below. Please make sure to
include all of your work on the sheets provided.
Part 1:
1) B. The sample is drawn from the population of actors and actresses in Los Angeles,
so the sample can only represent that population.
2) i) Mean = 2060
ii) Median = 50
iii) Standard deviation = 4439
iv) Interquartile range = Q3 – Q1 = 5100 – 25 = 5075
v) A. Suppose that 10,000 goes up to 10,100. The new mean is 2080, but the median is
still 50 and there is still no mode.
vi) 200. Define x = sixth actor’s salary
20 30 50 200 10000 1750, so 200
6
x
Mean x
3) i) P(had plastic surgery and afraid of aliens) = 40/100 = 0.4
ii) P(afraid of aliens given that had plastic surgery) = 40/55 = 0.73
Out of the 55 aliens who have had plastic surgery, 40 are afraid of aliens.
iii) B. P(afraid of aliens) = 60/100 = 0.6
P(afraid of aliens given that had plastic surgery) = 0.73,
So P(afraid of aliens) ≠ P(afraid of aliens given that had plastic surgery)
Actors who have had plastic surgery are more likely to be afraid of aliens
