Question

Dennis wants to buy a card for his wife. Dennis calculates the amount of the card as $4.50. The actual price of a card is $4. What is Dennis’s percent error?

Answer 1

Answer: $Percent\ error=12.5\%$

Step-by-step explanation:

For this exercise you need to apply the formula for calculate the percent error. This is the following:

$Percent\ error=\frac{|E-T|}{|T|}*100$

Where "E" represents the experimental value and "T" represents the theoretical value.

According to the information given in the exercise, you know that Dennis calculates the amount of the card as $4.50, but actually it is $4. Then, you can identify that:

$E=4.50\\\\T=4$

Therefore, knowing those values you can substitute them into the formula and then you must evaluate, in order to calculate  Dennis’s percent error.

You get that this is:

$Percent\ error=\frac{|4.50-4|}{|4|}*100\\\\Percent\ error=\frac{0.50}{4}*100\\\\Percent\ error=12.5\%$