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
1. Distance between points is 7
2. Distance between points is 6
3. Distance between points is 10
4. Distance between points is 6
5. Distance between points is 4
The solving for the first one should be like this

And the next part

After these manipulations just multiply them

And finally you need to square and simplify for the completed answer
Answer:
Step-by-step explanation:
