you don't need to know this for real life situations but for school you do need to know it, i dont know how to do this but here's a link to the same question you have but it's explained on how to solve it
https://www.wyzant.com/resources/answers/499729/fireworks_can_go_up_to_1000_feet_in_around_3_seconds_what_s_is_it_s_average_vertical_speed_in_feet_per_second_and_miles_per_hour
((Also i'm a fellow ARMY as well =) ))
A = π r^2
A = 9^2 <span>π
</span>A = 81<span>π
if using </span>π = 3.14 then
A = 3.14 x 81 = 254.47 ft^2
answer: 81π ft^2 or 254.47 ft^2
hope that helps
The base is 30.
Hopefully I got this correct, not 100%
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 


