Texas Instruments TI-73 - Manual (Page 65)

60
Using the TI-73: A Guide for Teachers Probability
© 1998 T EXAS I NSTRUMENTS I NCORPORATED
3. Compare the group experimental probabilities with the
theoretical probabilities from the tree diagram.
a. Go to L 3
and calculate the group probabilities by
dividing each entry in L 3
by the total number of
trials (sum of L 2
).
3 " $ to highlight
L 3 (See screen at the right.)
- v Z F - v " " J
- v Z E b
b. In L 4
enter the frequencies from the tree diagram.
(See screen at the right.)
" to the first line of
L 4
Enter the frequencies from the tree diagram. Press
b after each list item.
c. Then in L 5
, find the theoretical probabilities by
dividing the frequencies in L 4
by the total of L 4
,
which is 32.
" $ to highlight
L 5
- v Q F - v " " J
- v Q E b
➪
Counting the frequency of
the points on the tree
diagram resulted in the
frequencies listed in L 4 .
4. Compare the experimental probabilities in L 3
to the
theoretical probabilities in L 5
. (See screen at the right.)
Wrap-up for Part B
Have students write in their journals the difference
between experimental and theoretical probability.
Assessment Suggestion for Part B
Ask students: Suppose you toss 4 coins. How many
heads are most likely to occur?
Explain.
Extensions
♦
Find the probability of two equally likely events using
combinations in Pascal’s Triangle.
♦
Plot a histogram using the theoretical probabilities.
♦
Draw a pie chart comparing frequencies to total
number of possible outcomes.