Two coins R and S are tossed. The 4 joint events HRHS, TRTS, HRTS, TRHS have probabilities 0.28, 0.18, 0.30, 0.24, respectively, where H represents head and T represents tail. Which one of the following is TRUE? A. The coin tosses are independent B. R is fair, S is not C. S is fair, R is not D. The coin tosses are dependent

The correct answer is D. The coin tosses are dependent.

The probability of getting heads on coin R is not the same for all four joint events. This means that the outcome of the toss of coin R depends on the outcome of the toss of coin S. Therefore, the coin tosses are dependent.

To explain each option in brief:

• Option A: The coin tosses are independent if the probability of getting heads on coin R is the same for all four joint events. This is not the case in this question, so option A is not correct.
• Option B: R is fair if the probability of getting heads on coin R is 0.5. This is not the case in this question, so option B is not correct.
• Option C: S is fair if the probability of getting heads on coin S is 0.5. This is not the case in this question, so option C is not correct.