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Find the following probabilities for the standard normal random variable: a. \(P(.3

Short Answer

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Answer: The probabilities for the given standard normal random variable are: a. \(P(.3<z<1.56) = 0.3227\) b. \(P(-.2<z<.2) = 0.1586\)

Step by step solution

01

Use the Z-table for the first interval (\(P(.3

To find the probabilities for the first interval, refer to the Z-table to look up the probabilities for \(z = .3\) and \(z = 1.56\). Based on the Z-table, we get: - \(P(z \le .3) = 0.6179\) - \(P(z \le 1.56) = 0.9406\)
02

Calculate the probability for the first interval

Now, we will subtract the probability for the lower limit from the probability for the upper limit to find the probability between these points: \(P(.3 < z < 1.56) = P(z \le 1.56) - P(z \le .3)\) \(P(.3 < z < 1.56) = 0.9406 - 0.6179 = 0.3227\) The probability for the first interval is 0.3227.
03

Use the Z-table for the second interval (\(P(-.2

Repeat the process for the second interval. Refer to the Z-table to look up the probabilities for \(z = -.2\) and \(z = .2\). Based on the Z-table, we get: - \(P(z \le -.2) = 0.4207\) - \(P(z \le .2) = 0.5793\)
04

Calculate the probability for the second interval

Again, subtract the probability for the lower limit from the probability for the upper limit to find the probability between these points: \(P(-.2 < z < .2) = P(z \le .2) - P(z \le -.2)\) \(P(-.2 < z < .2) = 0.5793 - 0.4207 = 0.1586\) The probability for the second interval is 0.1586. In summary, the probabilities for the given standard normal random variable are: a. \(P(.3<z<1.56) = 0.3227\) b. \(P(-.2<z<.2) = 0.1586\)

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