Answer:
2.85
Step-by-step explanation:
The z score is a score in statistics used to determine by how many standard deviations the raw score is above or below the mean. If the raw score is above the mean then the z score is positive while if the z score is negative then the z score is negative. The z score is given by:
[tex]z=\frac{x-\mu}{\sigma}\\ \\\mu=mean, \sigma=standard\ deviation, x=raw\ score\\\\Given \ that:\\\\\mu=16.3\ days, \sigma=4.8\ days.\\\\For\ x=30\ days:\\\\z=\frac{30-16.3}{4.8}\\ \\z=2.85[/tex]
