\( X \) is a normally distributed random variable with mean 37 and standard deviation 4 . What is the probability that \( X \) is less than 29 ? Use the \( 0.68-0.95-0.997 \) rule and write your answer as a decimal. Round to the nearest thousandth if necessary.
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To find the probability that \( X \) is less than 29, we can use the properties of the normal distribution. First, we need to determine how many standard deviations away 29 is from the mean. The mean \( \mu = 37 \) and the standard deviation \( \sigma = 4 \). We calculate the z-score for \( X = 29 \): \[ z = \frac{X - \mu}{\sigma} = \frac{29 - 37}{4} = \frac{-8}{4} = -2 \] A z-score of -2 means that 29 is 2 standard deviations below the mean. According to the 68-95-99.7 rule, about 95% of the data lies within 2 standard deviations from the mean, which means: - 2.5% lies below \( \mu - 2\sigma \) (which corresponds to a z-score of -2). - 2.5% lies above \( \mu + 2\sigma \). Thus, the probability that \( X \) is less than 29 is approximately 0.025. So, the answer is \( 0.025 \).