
Explanation:
The question is asking for the probability that a financial variable, X, which is assumed to follow a normal distribution with a mean (μ) of 40 and a standard deviation (σ) of 14, falls outside the range of 12 to 61.
To solve this, we first convert the given values of X into z-scores using the formula .
For the lower bound (12):
For the upper bound (61):
Next, we look up these z-scores in a standard normal distribution table (Z-table) to find the probabilities associated with them.
The probability that Z is less than -2 (P(Z < -2)) is 0.0228. This represents the probability that X is less than 12.
The probability that Z is greater than 1.5 (P(Z > 1.5)) is 0.0668. This represents the probability that X is greater than 61.
To find the combined probability that X is either less than 12 or greater than 61, we add these two probabilities together:
This means there is an 8.96% chance that the variable X will be outside the range of 12 to 61, which corresponds to option C.
Ultimate access to all questions.
No comments yet.