Cogito
Probability and Statistics · Chapter 5 · Lesson 3
Binomial Situations
Counting successes in a fixed number of tries.
12 problems · about 22 minutes · TEKS P.S.2.G, S-MD.A.3
Figure — use these to answer the problems
Warm Up
Straightforward practice. Get the method working first.
5 problemsn = 60, p = 0.5. What is the mean number of successes?
AnswerWhy is drawing cards without replacement not binomial?
- The trials are not independent, since the deck changes.
- There are too many cards.
n = 20, p = 0.5. Mean number of successes?
Answern = 50, p = 0.2. Mean?
Answer5 tosses. How many patterns have exactly 2 heads?
Answer
Build It Up
The same ideas with more to keep track of.
3 problems4 tosses of a fair coin. P(exactly 2 heads), as a decimal to three places?
AnswerHow many conditions must a binomial setting satisfy?
Answern = 100, p = 0.3. Mean?
Answer
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
4 problemsWhich settings are binomial?
- Tossing a coin 10 times and counting heads
- Asking 50 people a yes-or-no question
- Tossing until the first head appears
- Drawing 5 cards without replacement
- Tick every box that applies.
n = 12, p = 0.25. Mean?
AnswerThe Mean
40 tosses of a fair coin. What is the mean number of heads?
AnswerThe Patterns
4 coin tosses. How many patterns have exactly 2 heads?
Answer