Answer:
68% of the pizzas are delivered between 24 and 30 minutes
Step-by-step explanation:
First we calculate the Z-scores
We know the mean and the standard deviation.
The mean is:
[tex]\mu=27[/tex]
The standard deviation is:
[tex]\sigma=3[/tex]
The Z-score formula is:
[tex]Z = \frac{x-\mu}{\sigma}[/tex]
For [tex]x=24[/tex] the Z-score is:
[tex]Z_{24}=\frac{24-27}{3}=-1[/tex]
For [tex]x=30[/tex] the Z-score is:
[tex]Z_{30}=\frac{30-27}{3}=1[/tex]
Then we look for the percentage of the data that is between [tex]-1 <Z <1[/tex] deviations from the mean.
According to the empirical rule 68% of the data is less than 1 standard deviations of the mean. This means that 68% of the pizzas are delivered between 24 and 30 minutes
