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What are the conventional values of skewness and kurtosis of a normal random variable?
A
Skewness=0, kurtosis=3
B
Skewness=1, kurtosis=3
C
Skewness=0, kurtosis=2
D
Skewness=0, kurtosis=4
Explanation:
The correct answer is A. For a normal distribution:
Skewness = 0: A normal distribution is perfectly symmetrical around its mean, so its skewness (third standardized moment) is zero.
Kurtosis = 3: The kurtosis (fourth standardized moment) of a normal distribution is 3. This is often referred to as "mesokurtic."
Key concepts:
Option B is incorrect because skewness is 0, not 1. Option C is incorrect because kurtosis is 3, not 2. Option D is incorrect because kurtosis is 3, not 4.