Answer: Crashes due to pilot error is the most serious threat to aviation safety as it has highest relative frequency.
Step-by-step explanation:
Since we have given that
Number of crashes due to pilot error = 699
Number of crashes due to other human error = 88
Number of crashes due to mechanical problems = 156
Number of crashes due to sabotage = 164
Total number of crashes = 699+88+156+164 = 1167
So, Relative frequency distribution :
Pilot error = 
Human error = 
Mechanical problems = 
Sabtoge = 
Crashes due to pilot error is the most serious threat to aviation safety as it has highest relative frequency.
It’s 0
-2 squared is 2 times (-1/2) is -2
8 / -2 squared is 2
So 2+-2 = 0
Answer: The answer is (a) JD should also subtract the areas of eight hidden surfaces.
Step-by-step explanation: Given that the sculpture consists of five identical prisms and he says the surface area of the sculpture is 4 times the surface area of one prism. We are to choose which one of the given four options are correct.
Since JD is calculating the surface area of the sculpture, consisting of five prisms. So, there will be eight hidden surfaces of the five prisms which will not be in count. Hence, he must subtract the areas of those eight hidden surfaces.
Please see the attached figure for more understanding, where prism A has 1 hidden surface, B has 2 hidden surfaces, C has 2 hidden surfaces, D has 2 hidden surfaces and E has 1 hidden surface.
Thus, the correct option is (a).