The weather report says that in the following 60 days, 24 days will be cloudy, 15 days will be rainy, and 10 days will be cloudy and rainy. Let event A represent cloudy days and event B represent rainy days. Are the events A and B independent or dependent, and why? (1 point) Responses dependent, because P(A)≠P(B) dependent, because P(A)≠P(B) dependent, because P(A)=P(B) dependent, because cap p times cap A is equal to cap p times cap b independent, because P(A and B)=P(A)⋅P(B) independent, because P(A and B)=P(A)⋅P(B) dependent, because P(A and B)≠P(A)⋅P(B)

1 answer

To determine whether events A (cloudy days) and B (rainy days) are independent or dependent, we can use the definition of independent events:

Events A and B are independent if and only if: \[ P(A \cap B) = P(A) \cdot P(B) \]

Where:

  • \( P(A \cap B) \) is the probability that both events A and B occur (i.e., a day that is both cloudy and rainy).
  • \( P(A) \) is the probability of event A occurring (i.e., a cloudy day).
  • \( P(B) \) is the probability of event B occurring (i.e., a rainy day).

From the information provided, we have the following:

  • Total days = 60
  • Cloudy days (Event A) = 24
  • Rainy days (Event B) = 15
  • Cloudy and rainy days (Event A and B) = 10

Now we can calculate the probabilities:

  1. \( P(A) = \frac{24}{60} = 0.4 \)
  2. \( P(B) = \frac{15}{60} = 0.25 \)
  3. \( P(A \cap B) = \frac{10}{60} \approx 0.1667 \)

Now we check if \( P(A \cap B) = P(A) \cdot P(B) \):

Calculating \( P(A) \cdot P(B) \): \[ P(A) \cdot P(B) = 0.4 \cdot 0.25 = 0.1 \]

Comparing:

  • \( P(A \cap B) = 0.1667 \)
  • \( P(A) \cdot P(B) = 0.1 \)

Since \( P(A \cap B) \neq P(A) \cdot P(B) \), this indicates that events A and B are dependent.

Thus, the correct response is:

dependent, because P(A and B) ≠ P(A)⋅P(B)