a. To find the probability that at least one of the stocks will rise in price, use the formula for the probability of the union of two events: \( P(A \cup B) = P(A) + P(B) - P(A \cap B) \). Calculate \( P(A \cap B) \) using the conditional probability \( P(A \mid B) \).
b. Events are mutually exclusive if they cannot both occur at the same time, i.e., \( P(A \cap B) = 0 \). Check if this condition holds.
c. Events are independent if the occurrence of one does not affect the probability of the other, i.e., \( P(A \mid B) = P(A) \). Check if this condition holds.
To find the probability that both stocks \( A \) and \( B \) will rise, use the conditional probability formula:
\[
P(A \cap B) = P(A \mid B) \times P(B) = 0.50 \times 0.60 = 0.30
\]
The probability that at least one of the stocks will rise is given by the formula for the union of two events:
\[
P(A \cup B) = P(A) + P(B) - P(A \cap B) = 0.40 + 0.60 - 0.30 = 0.70
\]
Thus, the probability that at least one stock will rise is \( \boxed{0.70} \).
Events \( A \) and \( B \) are mutually exclusive if \( P(A \cap B) = 0 \). Since \( P(A \cap B) = 0.30 \), the events are not mutually exclusive. Therefore, the answer is \(\boxed{\text{No because } P(A \cap B) \neq 0}\).
Events \( A \) and \( B \) are independent if \( P(A \mid B) = P(A) \). Given \( P(A \mid B) = 0.50 \) and \( P(A) = 0.40 \), these probabilities are not equal, indicating that the events are not independent. Therefore, the answer is \(\boxed{\text{No because } P(A \mid B) \neq P(A)}\).
- Probability that at least one stock will rise: \(\boxed{0.70}\)
- Are events \( A \) and \( B \) mutually exclusive? \(\boxed{\text{No because } P(A \cap B) \neq 0}\)
- Are events \( A \) and \( B \) independent? \(\boxed{\text{No because } P(A \mid B) \neq P(A)}\)