The time spent waiting in line is approximately normally distributed. The mean waiting time is 4 minutes and the standard deviation of the waiting time is 3 minutes. Find the probability that a person will wait for more than 1 minute. Round your answer to four decimal places.

The time spent waiting in line is approximately normally distributed The mean waiting time is 4 minutes and the standard deviation of the waiting time is 3 minu class=

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Solution:

Given:

[tex]\begin{gathered} \mu=4\text{ minutes} \\ \sigma=3\text{ minutes} \\ x=1\text{ minute} \end{gathered}[/tex]

Using the Z-score formula, the Z-score of the data is gotten below.

[tex]Z=\frac{x-\mu}{\sigma}[/tex]

Hence,

[tex]\begin{gathered} Z=\frac{1-4}{3} \\ Z=\frac{-3}{3} \\ Z=-1 \end{gathered}[/tex]

From the Z-scores table, the probability that a person will wait for more than 1 minute is;

[tex]\begin{gathered} P(x>Z)=0.84134 \\ \\ To\text{ four decimal places;} \\ P(x>Z)=0.8413 \end{gathered}[/tex]

Therefore, to four decimal places, the probability that a person will wait for more than 1 minute is 0.8413