1. Wharton School students who graduated in the class of 2005 were surveyed to obtain
employment information. There were 625 graduates, but only 400 returned the survey.
Sixty six respondents did not have a job at the time of the survey. The students with

I. Exploring Data: Describing patterns and departures from patterns
A. Constructing and interpreting graphical displays of distributions of
univariate data (dotplot, stemplot, histogram, cumulative frequency plot)
1. Center and spread
1. Construct a stem

1. Consider the experiment of tossing a coin thrice.
i.
List the experimental outcomes.
ii.
Define a random variable that represents the number of heads occurring on
these tosses.
iii.
Show what value the random variable would assume for each of the
exper

1. Sampling distribution of a sample mean
1. A population has a mean of 200 and a standard deviation of 50. A simple random sample
of size 100 will be taken and the sample mean x will be used to estimate the
population mean.
i.
What is the expected value

1. A soft drink machine can be regulated so that it discharges an average of MU ounces per cup. If
the ounces of fill are normally distributed with standard deviation equal to .3 ounces, give the
setting for MU so that eight-ounce cups will overflow only

1. Let
X
represent the number of weekly credit card purchases a person makes, and
Y
the
number of credit cards a person owns. Suppose the bivariate table for the two variables looks as
follows
X /Y
0
1
2
3
Total
1
0.08
0.10
0.10
0.02
0.3
2
0.08
0.05
0.22

Tutorial Sheet 4
Discrete Random Variables and Probability Distribuions
1. Starting at a fixed time, each car entering an intersection is observed to see whether it turns
left (L), right (R), or goes straight ahead (A). The experiment terminates as soon a

Tutorial Sheet
Day 3
1. Four universities1, 2, 3, and 4are participating in a basketball tournament. In the first
round, 1 will play 2 and 3 will play 4. Then the two winners will play for the championship,
and the two losers will also play. One possible