Answer:
[tex] \mu -2\sigma = 24-2*3= 18[/tex]
[tex] \mu -2\sigma = 24+2*3= 30[/tex]
So then we can conclude that we expect the middle 95% of the values within 18 and 30 minutes for this case
Step-by-step explanation:
For this case we can define the random variable X as the amount of time it takes her to arrive to work and we know that the distribution for X is given by:
[tex] X \sim N(\mu = 24, \sigma =3)[/tex]
And we want to use the empirical rule to estimate the middle 95% of her commute times. And the empirical rule states that we have 68% of the values within one deviation from the mean, 95% of the values within two deviations from the mean and 99.7 % of the values within 3 deviations from the mean. And we can find the limits on this way:
[tex] \mu -2\sigma = 24-2*3= 18[/tex]
[tex] \mu -2\sigma = 24+2*3= 30[/tex]
So then we can conclude that we expect the middle 95% of the values within 18 and 30 minutes for this case