Question

Ron is planning for the back-to-school rush at his store. Last year he estimated that he would need 168 notebooks, but he sold 200 notebooks. What was the percent error of Ron’s estimate?

Answer 1

I) 30 × 4 + (x - 30) × 5 < 200 

(II) 20 × 4 + (x - 20) × 5 > 200 


Restated: 

(I) 120 + 5x - 150 < 200; 5x < 230 

(II) 80 + 5x - 100 > 200; 5x > 220 

220 < 5x < 230 
44 < x < 46 

There are exactly 45 students in the class.

Answer 2

Answer:

Percentage error of Ron’s estimate is 16%.

Step-by-step explanation:

Formula

$Percentage\ error = \frac{Change\ in\ value\times 100}{Exact\ value}$

Where

Change in value = |Approx value - Exact value|

As given

Ron is planning for the back-to-school rush at his store.

Last year he estimated that he would need 168 notebooks, but he sold 200 notebooks.

Approx value = 168

Exact value = 200

Thus

Change in value = |168 - 200|

Change in value = |32|

Change in value = 32

Put all the values in the formula

$Percentage\ error = \frac{32\times 100}{200}$

$Percentage\ error = \frac{3200}{200}$

$Percentage\ error = \frac{32}{2}$

Percentage error = 16%

Therefore the percentage error of Ron’s estimate is 16%.