Final answer:
To find the constant k, we add up all the probabilities in the joint probability mass function and set the sum equal to 1. Solving for k, we find that k = 6.67.
Step-by-step explanation:
To find the constant k, we need to use the fact that the sum of all probabilities in a joint probability mass function is equal to 1. So we add up all the probabilities given and set the sum equal to 1:
0.01k + 0.02k + 0.05 + 0.02k + 0.1 + 0.05 + 0.03 + 0.12 + 0.2 + 0.15 + 0.06 + 0.15 = 1
Combining like terms, we get:
0.06k + 0.6 = 1
Subtracting 0.6 from both sides, we have:
0.06k = 0.4
Dividing both sides by 0.06, we get:
k = 6.67