Sample Midterm - SAMPLE MIDTERM EXAM STAT 53-10 Spring 2006...

SAMPLE MIDTERM EXAM
STAT 53-10
Spring 2006
Answer all the questions. Please show full work for partial credit.
1) Consider the following data on the number of hits to a Library website on 14
randomly picked days:
390 406 446 420 370 328 410 320 368 392 280 325 382 290
(a) (12 points) Construct a box plot for the above data?
(b) (4 points) Is the distribution symmetric? Explain.
2) (18 points) The number of passengers in a car on a freeway is a random variable
with the following probability distribution:
X 1 2 3 4 5
P(x) 0.4 - 0.15 0.1 0.05
(a) Find the probability that there are at most two passengers in a car
(b) Find the mean number of passengers in a car.
(c) Find the probability that the number of passengers in a car is within 1
standard deviation from the mean.
3) (15 points) A study of the behavior of large number of drug offenders after
treatment for drug abuse suggests that the likelihood of conviction within a two-
year period after treatment may depend on the offender’s education. The