The length of giselle`s arm is 27 inches. the length of her lower arm is 17 inches. about what percent of giselle`s arm is her lower arm?

Set up a proportion:
17 =  x
27   100
Cross multiply:
1700 = 27x     (now, divide to solve for x)
/27       /27
x = 62.962962...
When rounded, Giselle's lower arm is 62.96% of her arm.
Hope this helps!