\( X \) is a normally distributed random variable with mean 23 and standard deviation 2 . What is the probability that \( X \) is between 24 and 96 ? Write your answer as a decimal rounded to the nearest thousandth.
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To find the probability that \( X \) is between 24 and 96 for a normally distributed random variable with a mean of 23 and a standard deviation of 2, we can standardize the variable using the Z-score formula: \[ Z = \frac{X - \mu}{\sigma} \] Where \( \mu \) is the mean and \( \sigma \) is the standard deviation. 1. For \( X = 24 \): \[ Z = \frac{24 - 23}{2} = \frac{1}{2} = 0.5 \] 2. For \( X = 96 \): \[ Z = \frac{96 - 23}{2} = \frac{73}{2} = 36.5 \] Now, we find the probabilities corresponding to these Z-scores using the standard normal distribution table or a calculator: - The probability of \( Z < 0.5 \) is approximately 0.6915. - The probability of \( Z < 36.5 \) is practically 1 (as it is way off the standard Z-table). To find the probability that \( X \) is between 24 and 96, we subtract the two probabilities: \[ P(24 < X < 96) = P(Z < 36.5) - P(Z < 0.5) \approx 1 - 0.6915 = 0.3085 \] Thus, the probability that \( X \) is between 24 and 96 is approximately 0.309 when rounded to the nearest thousandth.