Problem

Let $\mathrm{x}$ be a continuous random variable that is normally distributed with mean $\mu=24$ and standard deviation $\sigma=2$. Using the accompanying standard normal distribution table, find $P(26 \leq x \leq 28)$.
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The probability is (Round to four decimal places as needed.)

Answer

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Answer

Final Answer: The probability that a normally distributed random variable falls between 26 and 28 is approximately \(\boxed{0.1359}\).

Steps

Step 1 :Let \(x\) be a continuous random variable that is normally distributed with mean \(\mu=24\) and standard deviation \(\sigma=2\). We are asked to find the probability that \(x\) falls between 26 and 28, i.e., \(P(26 \leq x \leq 28)\).

Step 2 :To solve this, we first convert the values 26 and 28 to z-scores, which are standard deviations from the mean. The formula for a z-score is \((x - \mu) / \sigma\).

Step 3 :Using this formula, we find that the z-score for 26 is 1.0 and the z-score for 28 is 2.0.

Step 4 :We then use the standard normal distribution table to find the probabilities associated with these z-scores. The probability that \(x\) is between 26 and 28 is the same as the probability that \(z\) is between the z-score of 26 and the z-score of 28.

Step 5 :From the standard normal distribution table, we find that the probability associated with a z-score of 1.0 is approximately 0.8413 and the probability associated with a z-score of 2.0 is approximately 0.9772.

Step 6 :We subtract the smaller probability from the larger one to get the final answer. So, \(P(26 \leq x \leq 28) = P(z_2) - P(z_1) = 0.9772 - 0.8413 = 0.1359\).

Step 7 :Final Answer: The probability that a normally distributed random variable falls between 26 and 28 is approximately \(\boxed{0.1359}\).

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