A recent study found that cedar trees by ancient indigenous settlements grow tal
ID: 3040800 • Letter: A
Question
A recent study found that cedar trees by ancient indigenous settlements grow taller than cedar trees not by indigenous settlements. This is due to the fact that indigenous people would place clam shells in the ground to help with water drainage. This in turn contributed to tree growth. The probability of a cedar tree being over 90m tall by an indigenous settlement is 0.20.
If we take a random sample of 20 cedar trees growing near an indigenous settlement, what is the probability that half of them will be over 90m?
Explanation / Answer
n = 20
p = 0.2
P(X = x) = nCx * px * (1 - p)n - x
P(X = 10) = 20C10 * (0.2)10 * (0.8)10 = 0.002