Question

practice

1. in 2014, the attendance at jefferson schools fall festival was 650. in 2015, the attendance was 575. what was the percent change in attendance from 2014 to 2015?

round to the nearest whole percent.

1. melissa estimated that she would read 250 pages last week. she read 290 pages. what is the percent error of melissas estimate? round to the nearest whole percent.

Explanation:

Problem 1: Percent Change in Attendance

Step 1: Find the change in attendance

The formula for change is \( \text{New Value} - \text{Old Value} \). Here, old attendance (2014) is 650, new attendance (2015) is 575. So, \( 575 - 650 = -75 \). The negative sign indicates a decrease.

Step 2: Calculate percent change

The formula for percent change is \( \frac{\text{Change}}{\text{Original Value}} \times 100 \). Substituting the values: \( \frac{-75}{650} \times 100 \approx -11.54\% \). Rounding to the nearest whole percent, we take the absolute value for the magnitude of change (since percent change can be negative for decrease, but we can report the decrease as a percentage). So it's approximately a 12% decrease (or -12% change).

Step 1: Find the absolute error

Absolute error is \( |\text{Actual Value} - \text{Estimated Value}| \). Actual pages read: 290, estimated: 250. So, \( |290 - 250| = 40 \).

Step 2: Calculate percent error

The formula for percent error is \( \frac{\text{Absolute Error}}{\text{Estimated Value}} \times 100 \). Substituting the values: \( \frac{40}{250} \times 100 = 16\% \).

Answer:

The percent change in attendance from 2014 to 2015 is approximately \(\boldsymbol{-12\%}\) (or a 12% decrease).

Problem 2: Percent Error in Melissa's Estimate