Answer:
0.15866
Explanation:
The term at most 9 means = less than or equal to 9
This represented as x ≤ 9
We solve using the z score formula
z = (x-μ)/σ, where
x is the raw score = ≤ 9
μ is the population mean = 10
σ is the population standard deviation = 1
z = 9 - 10/1
z = -1
Probability value from Z-Table:
P(x ≤ 9) = 0.15866
Therefore, the probability of selecting a number that is at most 9 is 0.15866