Final answer:
To determine the probability P(x < 9) in a normal distribution with a mean of 10 and a standard deviation of 2, use the z-score formula and the corresponding z-table or calculator.
Step-by-step explanation:
To determine the probability P(x < 9) in a normal distribution with a mean of 10 and a standard deviation of 2, we need to find the area under the curve to the left of 9. We can convert this value to a z-score using the formula:
z = (x - mean) / standard deviation
Let's substitute in the given values:
z = (9 - 10) / 2 = -0.5
We can then use a z-table or a calculator to find the corresponding probability which is approximately 0.3085.