Answer: A) 0.5 pound
Explanation:
Let x be the actual or the ideal measure of the weight of the box and E be the error .
Given : Beatriz determined the margin of error as 23.5 pounds to 24.5 pounds.
Then , we have the following equations :-
![x-E=23----------------------(1)\\\\ x+E=24.5----------------(2)](https://img.qammunity.org/2019/formulas/mathematics/high-school/y54rwzp2xoxtbt4i0uirsecwppbylhlxbq.png)
Subtract (1) from (2) , we get
![2E=24.5-23.5\\\\|rightarrow\ 2E=1\\\\\Rightarrow\ E=(1)/(2)=0.5](https://img.qammunity.org/2019/formulas/mathematics/high-school/6n047ikzpksdguw2egrwl36bg1zoainyrg.png)
Hence, the greatest possible error for her actual measurement was 0.5 pounds