Answer:
Approximately 1.9 standard deviation below mean.
Explanation:
We have been given that the typical amount of sleep per night that adults get has a bell-shaped distribution with a mean of 7.5 hours and a standard deviation of 1.3 hours. Last night you slept for 5 hours.
We will use z-score formula to solve our given problem as z-score tells that a data point is how many standard deviation above or below mean.
, where,
z = z-score,
x = Sample score,
= Mean,
= Standard deviation.
![z=(5-7.5)/(1.3)](https://img.qammunity.org/2020/formulas/mathematics/college/txld6cddiug3zz4xf27h814ushrea020se.png)
![z=(-2.5)/(1.3)](https://img.qammunity.org/2020/formulas/mathematics/college/ofus9xzmtxyslfk04s1j0wrvgua2sxcooc.png)
![z=-1.92307](https://img.qammunity.org/2020/formulas/mathematics/college/ojov77g4oqtbp8bcy4a5o8xnjimcxp3ipb.png)
Therefore, you are approximately 1.9 standard deviation below mean.