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1. in a community 70% of households have kids. of the households with k…

Question

  1. in a community 70% of households have kids. of the households with kids, 60% have a pet. and of the households that dont have kids, 50% have a pet. make a tree diagram of this situation.

(a) p(household has kids and has a pet)
(b) p(household that does not have kids and does have a pet)
(c) p(household has a pet)

  1. one hospital employs 200 nurses. nurses at the hospital can work either in the neonatal unit or as a pediatrician. 75% of all the nurses are female. 55% of all the female nurses work in the neonatal unit. 5% of male nurses work as a pediatrician. make a tree diagram of this situation.

(a) p(male)
(b) p(female and neonatal)
(c) p(male and pediatrician)
(d) p(pediatrician)

Explanation:

Problem 1 (Household and Pet Probability)
Part (a)

Step1: Identify Probabilities

Let \( K \) be the event that a household has kids, \( P \) be the event that a household has a pet. We know \( P(K) = 0.7 \) and \( P(P|K) = 0.6 \).

Step2: Apply Multiplication Rule

The multiplication rule for conditional probability is \( P(K \cap P) = P(K) \times P(P|K) \). Substitute the values: \( 0.7 \times 0.6 = 0.42 \).

Step1: Identify Probabilities

Let \( K^c \) be the event that a household does not have kids. \( P(K^c) = 1 - 0.7 = 0.3 \), and \( P(P|K^c) = 0.5 \).

Step2: Apply Multiplication Rule

Using \( P(K^c \cap P) = P(K^c) \times P(P|K^c) \), substitute: \( 0.3 \times 0.5 = 0.15 \).

Step1: Use Total Probability

The event \( P \) can occur in two ways: with kids (\( K \cap P \)) or without kids (\( K^c \cap P \)). We found \( P(K \cap P) = 0.42 \) and \( P(K^c \cap P) = 0.15 \).

Step2: Sum the Probabilities

\( P(P) = P(K \cap P) + P(K^c \cap P) = 0.42 + 0.15 = 0.57 \).

Answer:

\( 0.42 \)

Part (b)