3 + (2 + 8)^2 / 4 * (1/2)^4
3 + 10^2 / 4 * (1/2)^4
3 + 100/4 * (1/2)^4
3 + 25 * 1/16
3 + 25/16
48/16 + 25/16
73/16
4 9/16 <==
Ok...we got 250 people
30% are French, 35% are Americans, 20% are Germans....thats 85%.
This means 15% are from other countries
3 not from other countries...
0.85 * 0.85 * 0.85 = 0.6
0.6(250) = 150 students <===
You cannot find the percent error of data without knowing the true length of the rope, as percent error is essentially a comparison between what you measured and what it actually is.