Respuesta :
Answer:
0.0082 = 0.82% probability that a randomly selected person will wait more than 42 seconds.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Mean wait time of 30 seconds and a population standard deviation of 5 seconds.
This means that [tex]\mu = 30, \sigma = 5[/tex]
What is the probability that a randomly selected person will wait more than 42 seconds?
This is 1 subtracted by the pvalue of Z when X = 42. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{42 - 30}{5}[/tex]
[tex]Z = 2.4[/tex]
[tex]Z = 2.4[/tex] has a pvalue of 0.9918
1 - 0.9918 = 0.0082
0.0082 = 0.82% probability that a randomly selected person will wait more than 42 seconds.
