Problem

Let x be a continuous random variable that is normally distributed with mean μ=24 and standard deviation σ=2. Using the accompanying standard normal distribution table, find P(26x28).
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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 0.1359.

Steps

Step 1 :Let x be a continuous random variable that is normally distributed with mean μ=24 and standard deviation σ=2. We are asked to find the probability that x falls between 26 and 28, i.e., P(26x28).

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 (xμ)/σ.

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(26x28)=P(z2)P(z1)=0.97720.8413=0.1359.

Step 7 :Final Answer: The probability that a normally distributed random variable falls between 26 and 28 is approximately 0.1359.

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