Answer:
it doesnt want to load for me im sorry :(
Step-by-step explanation:
Answer:
a = 16.733
Step-by-step explanation:
Since this is a right triangle, we can use the Pythagorean theorem
a^2 + b^2 = c^2
a^2 + 9^2 = 19^2
a^2 = 19^2 - 9^2
a^2 = 361-81
a^2 =280
Taking the square root of each side
sqrt(a^2) = sqrt(280)
a = 16.73320053
Rounding to the nearest thousandth
a = 16.733
Answer:
Modification has not reduced the number of accidents.
Step-by-step explanation:

A B C D E F G H
Before modification 5 7 6 4 8 9 8 10
After modification 3 7 7 0 4 6 8 2
Difference -2 0 1 -4 -4 -3 0 -8
Mean of differences 
Standard deviation of differences = 
Formula of paired t test :

Df = n-1 = 8-1 =7

t critical> t calculated
So, We failed to reject null hypothesis
Hence modification has not reduced the number of accidents.