Answer:
Z-score = -1.38
Explanation:
The z-score measures how many standard deviations from the mean a data is
Therefore the z score is the quotient between the difference between a value and the mean and the standard deviation
![Z =(X-\mu)/(\sigma)](https://img.qammunity.org/2020/formulas/mathematics/high-school/se6vjmi65uw5q4e0pj5wd069jy9k513dd8.png)
Where
μ is the mean, x is a data of the population and
is the standard deviation
In this case
![\mu = 15\ g\\\\\sigma = 1.6\ g\\\\X = 17.2\ g](https://img.qammunity.org/2020/formulas/mathematics/high-school/aj0axb4m280koorwnarqdci11k2km9f67a.png)
Then the z-score is
![Z = (15-17.2)/(1.6)\\\\Z = -1.38](https://img.qammunity.org/2020/formulas/mathematics/high-school/j6obxssmoblfyqhbla9780wck41st9tjki.png)