Hypothesis testing

Many new stockbrokers resist giving presentations to bankers and certain
other groups. Sensing this lack of self-confidence, management arranged
to have a confidence-building seminar for a sample of new stockbrokers
and enlisted Career Boosters for a three-week course. Before the first
session. Career Boosters measured the level of confidence of each
participant. It was measured again after the three-week seminar. The
before and after levels of self-confidence for the 14 in the course are
shown below. Self-confidence was classified as being either negative,
low, high, or very high.

Stockbroker Before Seminar After Stockbroker Before seminar After

J. Martin Negative Low F. Orphey Low Very High

Jagger Negative Negative Ford Low High

Hammer Low High Utz Negative Low

Jones Very High Low Murphy Low High

Cornwall Low High Arms Negative Low

Skeen Low High Pierre Low High

Simmer Negative High Walker Low Very High

The purpose of this study is to find whether Career Boosters was
effective in raising the self-confidence of the new stockbrokers. That
is, was the level of self-confidence higher after the seminar than
before? Use the .05 signficance level.

a. State the null and alternate hypotheses.

b. Using the .05 level of significance, state the decision rule- either
in words or in chart form.

c. Draw conclusions about the seminar offered by Career Boosters.