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Assume the random variable $X$ is normally distributed with mean $\mu=50$ and standard deviation $\sigma=7$. Compute the probability. Be sure to draw a normal curve with the area corresponding to the probability shaded.
\[
\mathrm{P}(35< \mathrm{X}< 57)
\]

Click the icon to view a table of areas under the normal curve.

Which of the following normal curves corresponds to $\mathrm{P}(35< \mathrm{X}< 57)$ ?
A.
$P(35< X< 57)=\square$
B.
c.
(Round to four decimal places as needed.)
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Answer

Thus, the probability that the random variable $X$ falls between 35 and 57 is approximately \(\boxed{0.8253}\).

Steps

Step 1 :Given that the random variable $X$ is normally distributed with mean $\mu=50$ and standard deviation $\sigma=7$, we are asked to compute the probability $P(35

Step 2 :We first standardize the values 35 and 57 using the formula $Z = \frac{X - \mu}{\sigma}$.

Step 3 :For $X=35$, we get $Z_1 = \frac{35 - 50}{7} = -2.142857142857143$.

Step 4 :For $X=57$, we get $Z_2 = \frac{57 - 50}{7} = 1.0$.

Step 5 :We then look up the probabilities corresponding to these Z-scores in the standard normal distribution table.

Step 6 :For $Z_1 = -2.142857142857143$, we get $P_1 = 0.016062285603828316$.

Step 7 :For $Z_2 = 1.0$, we get $P_2 = 0.8413447460685429$.

Step 8 :We subtract these probabilities to find the probability of $X$ falling between 35 and 57, i.e., $P = P_2 - P_1 = 0.8413447460685429 - 0.016062285603828316 = 0.8252824604647147$.

Step 9 :Thus, the probability that the random variable $X$ falls between 35 and 57 is approximately \(\boxed{0.8253}\).

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