A person attempting to lose weight on a diet weighed 175 lb on their home bathroom scale. An hour later at the doctor’s office, on a more accurate scale, the same person weighed 178.2 lb. Assuming there was no real change in weight in that hour and that the doctor’s scale gives the accepted weight, find the experimental error and percentage error between the two scales. Round all answers to the correct number of SDs
Confused? Please help! Sophomore in high school studying ACP Honors DC Chemistry.

The error of the bathroom scale is the difference between what it measured and the "true" weight as determined at the doctor's office. The percentage error would be that value of error expressed as a percentage of the true weight. As for SD's (I assume you mean standard deviation) you don't have data presented that allows determination of a population mean and standard deviation.