Use the worksheet to record your answers to the Compound Events portfolio activities. When you are finished, save your worksheet with your answers and submit it for a portfolio grade.

Mutually Inclusive and Exclusive Events – Portfolio
Use what you have learned about mutually inclusive and exclusive events. Apply the formula for calculating the probability of events A or B.

Question 1
There are four presidential candidates in a country. A street survey was conducted asking 2,500 registered voters which candidate they will vote for in the coming election. The table summarizes the results of the survey.

Survey Results of Voter Preferences for Presidential Candidates
Presidential Candidates
Number of Supporters
Candidate 1
250
Candidate 2
1,250
Candidate 3
450
Candidate 4
550
What is the probability of randomly selecting a person who will vote for Candidate 1 or 2?
If 1,000 more voters are surveyed, how many of them will likely prefer Candidate 3 or 4? Explain your answer.
Question 2
A basket of fruits contains 20 apples, 4 watermelon slices, and 12 oranges. If a piece of fruit is to be selected randomly from the box, what is the probability of selecting an apple or an orange?

Question 3
A survey of 80 employees was conducted asking about which meals they regularly eat at the office. Twenty employees eat breakfast at the office, 50 eat lunch, and 15 eat both breakfast and lunch. If an employee is randomly selected from this group, what is the probability of randomly selecting an employee who eats breakfast or lunch at the office?

Dependent and Independent Events – Portfolio
Use what you have learned about dependent and independent events. Apply the formula for calculating the probability of events A and B.

Question 4
Use an online spinner to generate a wheel with five equal sections. Use the letters of the word CLEAN as the labels.

Use the spinner to simulate the random selection of two letters with repetition from the word CLEAN. This will constitute one trial. The order of selection does not matter. For example, spinning an A and E is the same as spinning an E and A.
Conduct 30 trials. Summarize the results using a table.
Use your results to approximate the probability of spinning letters C and E.
Calculate the theoretical probability of spinning letters C and E. Compare the result with part (c).
Question 5
A large company plans to develop a private subdivision. There are 6 house models to choose from and, for each model, a client may opt to have a garage or a carport. Use A, B, C, D, E, and F as labels for the house models.

Design and run a simulation to generate frequencies that can be used to approximate the probability of a client who will choose model B with a car garage.
Use the results of the simulation to calculate the probability that a client will choose model B with a car garage.

1 answer

Mutually Inclusive and Exclusive Events – Portfolio

Question 1: There are four presidential candidates in a country with the following survey results:

  • Candidate 1: 250
  • Candidate 2: 1,250
  • Candidate 3: 450
  • Candidate 4: 550

Probability of Voting for Candidate 1 or 2:

Total number of voters surveyed: 2,500

Number of voters for Candidate 1 or Candidate 2:

  • Voters for Candidate 1 = 250
  • Voters for Candidate 2 = 1,250

Using the formula for probability of mutually exclusive events: \[ P(A \text{ or } B) = P(A) + P(B) \]

Calculating the probability: \[ P(1 \text{ or } 2) = \frac{250}{2500} + \frac{1250}{2500} = \frac{1500}{2500} = 0.6 \]

Thus, the probability of randomly selecting a person who will vote for Candidate 1 or 2 is 0.6 or 60%.

If 1,000 more voters are surveyed, how many will likely prefer Candidate 3 or 4?

The proportion of current voters for Candidate 3 and 4:

  • Candidate 3: 450
  • Candidate 4: 550
  • Total for Candidate 3 and 4 = 450 + 550 = 1,000

Thus, the proportion is \( \frac{1000}{2500} = 0.4 \)

If 1,000 more voters are surveyed: \[ 0.4 \times 1000 = 400 \] So, it can be expected that approximately 400 voters will prefer Candidate 3 or 4 among the new voters surveyed.


Question 2: A basket of fruits has 20 apples, 4 watermelon slices, and 12 oranges.

Probability of Selecting an Apple or an Orange:

Total number of fruits: \[ 20 + 4 + 12 = 36 \]

Number of apples or oranges: \[ 20 + 12 = 32 \]

Using the probability formula: \[ P(A \text{ or } O) = \frac{32}{36} = \frac{8}{9} \approx 0.8889 \]

Thus, the probability of selecting an apple or an orange is approximately 0.889 or 88.89%.


Question 3: In a survey of 80 employees:

  • Employees that eat breakfast: 20
  • Employees that eat lunch: 50
  • Employees that eat both breakfast and lunch: 15

Probability of Selecting an Employee who Eats Breakfast or Lunch:

Using the formula for the probability: \[ P(B \text{ or } L) = P(B) + P(L) - P(B \text{ and } L) \]

Calculating the individual probabilities: \[ P(B) = \frac{20}{80}, \quad P(L) = \frac{50}{80}, \quad P(B \text{ and } L) = \frac{15}{80} \]

Now substituting into the formula: \[ P(B \text{ or } L) = \frac{20}{80} + \frac{50}{80} - \frac{15}{80} = \frac{55}{80} = 0.6875 \]

Thus, the probability of randomly selecting an employee who eats breakfast or lunch is 0.6875 or 68.75%.


Dependent and Independent Events – Portfolio

Question 4: Using the letters of the word CLEAN, simulate a spinner to generate two letters (with repetition).

Table summarizing 30 trials: | Trial | Letter 1 | Letter 2 | Combination | |-------|----------|----------|---------------| | 1 | C | E | CE | | 2 | A | N | AN | | 3 | L | E | LE | | 4 | C | C | CC | | ... | ... | ... | ... | | 30 | E | A | EA |

(Below you will input the results from your trials and tally the combinations.)

Probability of Spinning Letters C and E:

  • Count the occurrences of combinations with C and E.
  • For example, if CE appears 4 times and EC appears 3 times, that’s 7 out of 30.

Calculating the theoretical probability:

  • There are a total of \(5 \times 5 = 25\) combinations.
  • Favorable outcomes for (C, E) or (E, C) = 2.

So, the theoretical probability is: \[ P(C \text{ and } E) = \frac{2}{25} = 0.08 \]

Comparison: Compare the experimental probability to the theoretical probability results.


Question 5: For a private subdivision with 6 house models (A, B, C, D, E, F) and options of garage or carport.

Simulation Summary: Generate random combinations to see how many select B with a car garage. For instance: | Count | Garage | Carport | |-------|--------|---------| | 1 | B | - | | 2 | C | - | | 3 | B | - | |... | ... | ... |

After running the simulation for a sufficient number of times:

If model B with a car garage appears 12 times out of 60 trials: \[ P(B \text{ with garage}) = \frac{12}{60} = 0.2 \]

Thus, the probability that a client will choose model B with a car garage is 0.2 or 20%.


Make sure to save your worksheet with your finalized answers for submission!