Percent Change and Percent Error

Front

What is percent change?

Back

Percent change is a measure of how much a quantity has increased or decreased relative to its original value, expressed as a percentage.

Front

How do you calculate percent change?

Back

Percent Change = ((New Value - Original Value) / Original Value) x 100%.

Front

What is percent error?

Back

Percent error is a measure of how inaccurate a measurement is, expressed as a percentage of the accepted value.

Front

How do you calculate percent error?

Back

Percent Error = (|Estimated Value - Actual Value| / Actual Value) x 100%.

Front

If a sweater originally costs $43 and is on sale for 20% off, what is the final price?

Back

Final Price = $43 - ($43 x 0.20) = $34.40.

Front

What is the percent decrease from $65.50 to $52.40?

Back

Percent Decrease = (($65.50 - $52.40) / $65.50) x 100% = 20%.

Front

If a shoe sales associate earned $300 in August and 8% more in September, how much did she earn in September?

Back

September Earnings = $300 + ($300 x 0.08) = $324.

Front

What is the formula for calculating the final price after a discount?

Back

Final Price = Original Price - (Original Price x Discount Rate).

Front

If the estimated attendance was 15,000 and the actual attendance was 12,500, what is the percent error?

Back

Percent Error = (|15,000 - 12,500| / 15,000) x 100% = 20%.

Front

How do you find the original price if you know the sale price and the discount percentage?

Back

Original Price = Sale Price / (1 - Discount Rate).