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Assume that adults have IQ scores that are normally distributed with a mean of \( \mu=100 \) and a standard deviation \( \sigma=15 \). Find the probability that a randomly selected adult has an IQ less than 118 . 1 Click to view page 1 of the table Click to view page 2 of the table. The probability that a randomly selected adult has an IQ less than 118 is (Type an integer or decimal rounded to four decimal places as needed.)

Ask by Davies Burns. in the United States
Feb 28,2025

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The probability that a randomly selected adult has an IQ less than 118 is approximately 0.8849.

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To find the probability that a randomly selected adult has an IQ less than 118, we first need to calculate the z-score using the formula: \[ z = \frac{X - \mu}{\sigma} \] where \( X \) is the IQ score (118), \( \mu \) is the mean (100), and \( \sigma \) is the standard deviation (15). Calculating the z-score: \[ z = \frac{118 - 100}{15} = \frac{18}{15} = 1.2 \] Next, we look up the z-score in the standard normal distribution table or use a calculator to find the probability. A z-score of 1.2 corresponds to a probability of approximately 0.8849. Therefore, the probability that a randomly selected adult has an IQ less than 118 is approximately **0.8849**.

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