Solve Percent Problems Review

Percent error is a measure of how inaccurate a measurement is, expressed as a percentage of the true value. It is calculated using the formula: Percent Error = |(Estimated Value - Actual Value)| / Actual Value * 100.

To calculate the sale price after a discount, subtract the discount amount from the original price. The discount amount can be found by multiplying the original price by the discount rate (as a decimal). Sale Price = Original Price - (Original Price * Discount Rate).

Percent change is calculated using the formula: Percent Change = (New Value - Original Value) / Original Value * 100.

If the estimated value is higher than the actual value, the percent error is positive. If the estimated value is lower, the percent error is negative.

To calculate a 15% tip on a $26 bill, multiply 26 by 0.15. Tip = 26 * 0.15 = $3.90.

To find the discount amount, multiply the original price by the discount rate (as a decimal). Discount Amount = Original Price * Discount Rate.

A percent change of 20% indicates that the new value is 20% greater than the original value.

A percent error of 25% means that the estimated value is 25% away from the actual value.

If the percent error is 20%, the actual weight can be calculated as: Actual Weight = Estimated Weight / (1 - Percent Error) = 8 / (1 - 0.20) = 10 pounds.

The discount amount is $900 * 0.30 = $270. The sale price is $900 - $270 = $630.