Respuesta :
Answer:
95% of the customers have to wait between 10 minutes and 26 minutes
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 18 minutes
Standard Deviation, σ = 4 minute
We are given that the distribution of amount of time is a bell shaped distribution that is a normal distribution.
Empirical Formula:
- Almost all the data lies within three standard deviation from the mean for a normally distributed data.
- About 68% of data lies within one standard deviation from the mean.
- About 95% of data lies within two standard deviations of the mean.
- About 99.7% of data lies within three standard deviation of the mean.
Now, we can write:
[tex]10 = 18-2(4) = \mu - 2(\sigma)\\26 = 18+2(4) = \mu + 2(\sigma)[/tex]
Thus, by empirical formula, 95% of the data lies within two standard deviations of the mean.
Thus, 95% of the customers have to wait between 10 minutes and 26 minutes
95% of customers have to wait between 10 minutes and 26 minutes
What is an empirical rule?
The empirical rules states that for a normal distribution, 68% of the values are within one standard deviation from the mean, 95% of the values are within two standard deviation from the mean and 99.7% of the values are within three standard deviation from the mean.
Given a mean of 18 minutes and a standard deviation of 4 minutes. Hence:
95% are within two standard deviation = 18 ± 2(4) = (10, 26)
95% of customers have to wait between 10 minutes and 26 minutes
Find out more on empirical rule at: https://brainly.com/question/10093236
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