3.81%
1) Since the total number of casualties was 3,754 we can find the percentage of 143 teens setting a proportion
3754 -------- 100%
143 ------------ x
Cross multiplying we have
3754x = 14300
x=14300/3754
x=3.809
x≈ 3.81%
2) So the percentage of teen driver deaths was in 2019, 3.81% of all fatalities.