Answer: 0.0228
Step-by-step explanation:
Given : The mean and the standard deviation of finish times (in minutes) for this event are respectively as :-

If the distribution of finish times is approximately bell-shaped and symmetric, then it must be normally distributed.
Let X be the random variable that represents the finish times for this event.
z score : 

Now, the probability of runners who finish in under 19 minutes by using standard normal distribution table :-

Hence, the approximate proportion of runners who finish in under 19 minutes = 0.0228
118.56. 31.2 x 3.8 = 118.56
B
The original value will be multiplied by 0.96 each time, making it 4% less than what it was.
Answer:
45.34
Step-by-step explanation:
you have to use the pythagorean theorem