Answer:

Step-by-step explanation:
Given: 76,45,64,80,92
Required: Determine the standard deviation
We start by calculating the mean

Where x-> 76,45,64,80,92 and n = 5



Subtract Mean (71.4) from each of the given data

Determine the absolute value of the above result

Square Individual Result

Calculate the mean of the above result to give the variance


Hence, Variance = 255.298
Standard Deviation is calculated by 



Answer:
It takes around 5s for each plane to travel their respective distances.
Step-by-step explanation:
C=pid
Since d=9m and pi=3.142, C=3.142*9m=28.278
Rounded to 1 decimal point =28.3