Answer: The value of P is 14.
Step-by-step explanation: To find the value of P, we can use the formula for the mean of a set of numbers:
mean = (sum of numbers) / (number of numbers)
We know that the mean of the set {6, 8, 9, P, 13} is 10. So we can write:
10 = (6 + 8 + 9 + P + 13) / 5
Multiplying both sides by 5, we get:
50 = 6 + 8 + 9 + P + 13
Combining like terms, we get:
50 = 36 + P
Subtracting 36 from both sides, we get:
14 = P
Therefore, the value of P is 14.