Answer:
Therefore, the percent error in 1. 20%
and the percent error in 2. 6%
Explanation:
Given:
1. In estimation of 30 people only 25 people attended.
2. In estimated length of 150 feet the measurement was 142 feet.
Now, in first case for the percent error we would calculate the difference between the people attended:

And then, we will get the percentage error :


.
Therefore, the percentage error is 20%.
Now, in second case for the percent error we would repeat the above process as done in first case:

And then:



Therefore, the percentage error is 6% (approximately).
Therefore, the percent error in 1. is 20%
and the percent error in 2. is 6%