We read your photo as:

Given P(A) = 0,48 and P(B) = 0,26. Calculate P(A or B) if: 1.1.1 A and B are mutually exclusive events. 1.1.2 A and B are independent events.

Mathematics

ScanSolve AI Answer

Step-by-step solution

5 steps

Here are the solutions to Question 1:

Part 1.1· 2 steps

Given P(A)=0.48P(A) = 0.48 and P(B)=0.26P(B) = 0.26.

  1. Calculate P(A or B)P(A \text{ or } B) for mutually exclusive events.

    For mutually exclusive events, the probability of A or B occurring is the sum of their individual probabilities.

    P(A or B)=P(A)+P(B)P(A \text{ or } B) = P(A) + P(B) P(A or B)=0.48+0.26P(A \text{ or } B) = 0.48 + 0.26 P(A or B)=0.74P(A \text{ or } B) = \boxed{\textbf{0.74}}
  2. Calculate P(A or B)P(A \text{ or } B) for independent events.

    For independent events, the probability of A and B occurring is the product of their individual probabilities: P(A and B)=P(A)×P(B)P(A \text{ and } B) = P(A) \times P(B).
    The general formula for P(A or B)P(A \text{ or } B) is:

    P(A or B)=P(A)+P(B)−P(A and B)P(A \text{ or } B) = P(A) + P(B) - P(A \text{ and } B)

    Substitute the formula for independent events:

    P(A or B)=P(A)+P(B)−(P(A)×P(B))P(A \text{ or } B) = P(A) + P(B) - (P(A) \times P(B)) P(A or B)=0.48+0.26−(0.48×0.26)P(A \text{ or } B) = 0.48 + 0.26 - (0.48 \times 0.26) P(A or B)=0.74−0.1248P(A \text{ or } B) = 0.74 - 0.1248 P(A or B)=0.6152P(A \text{ or } B) = \boxed{\textbf{0.6152}}

Part 1.2· 3 steps

A survey was conducted amongst 150 grade 11 learners.

  1. Write down the value of xx.

    From the table, the total number of boys is 80. The sum of boys' preferences for Netball, Soccer, and Rugby must equal this total.

    32+x+27=8032 + x + 27 = 80 59+x=8059 + x = 80 x=80−59x = 80 - 59 x=21x = \boxed{\textbf{21}}
  2. Calculate the probability that a learner is a boy and does not like netball.

    Total learners = 150.
    Number of boys = 80.
    Number of boys who like Netball = 32.
    Number of boys who do not like Netball = Total boys - Boys who like Netball

    =80−32=48= 80 - 32 = 48

    The probability is the number of boys who do not like netball divided by the total number of learners.

    P(boy and not netball)=48150P(\text{boy and not netball}) = \frac{48}{150}

    Simplify the fraction:

    P(boy and not netball)=2475=825P(\text{boy and not netball}) = \frac{24}{75} = \frac{8}{25} P(boy and not netball)=0.32P(\text{boy and not netball}) = \boxed{\textbf{0.32}}
  3. Determine if the events "being a boy" and "liking soccer" are independent.

    Two events A and B are independent if P(A and B)=P(A)×P(B)P(A \text{ and } B) = P(A) \times P(B).
    Let A be the event "being a boy".
    Let B be the event "liking soccer".

    Calculate the individual probabilities:
    Total learners = 150.
    Number of boys = 80.

    P(boy)=80150P(\text{boy}) = \frac{80}{150}

    Number of learners who like Soccer = 33.

    P(soccer)=33150P(\text{soccer}) = \frac{33}{150}

    Number of boys who like Soccer (value of xx) = 21.

    P(boy and soccer)=21150P(\text{boy and soccer}) = \frac{21}{150}

    Check for independence:
    Is P(boy and soccer)=P(boy)×P(soccer)P(\text{boy and soccer}) = P(\text{boy}) \times P(\text{soccer})?

    21150=80150×33150\frac{21}{150} = \frac{80}{150} \times \frac{33}{150}

    Calculate the right side:

    80150×33150=815×33150=2642250\frac{80}{150} \times \frac{33}{150} = \frac{8}{15} \times \frac{33}{150} = \frac{264}{2250}

    Simplify 2642250\frac{264}{2250} by dividing by 6:

    264÷62250÷6=44375\frac{264 \div 6}{2250 \div 6} = \frac{44}{375}

    Now compare this to the left side:

    21150\frac{21}{150}

    Simplify 21150\frac{21}{150} by dividing by 3:

    21÷3150÷3=750\frac{21 \div 3}{150 \div 3} = \frac{7}{50}

    Since 750≠44375\frac{7}{50} \neq \frac{44}{375} (or 0.14≠0.11730.14 \neq 0.1173), the events are not independent.

    The events "being a boy" and "liking soccer" are NOT independent.\boxed{\textbf{The events "being a boy" and "liking soccer" are NOT independent.}}
Was this helpful?

Still stuck on this one?

Ask a follow-up, and the answer starts from this question.

Got a different question?Ask your own question
Handwritten step-by-step solution preview

Handwritten Step-by-Step Solution

Get this as a handwritten image on WhatsApp — like a tutor wrote it for you.

Try on WhatsApp