Answer:10 Seconds
Step-by-step explanation:
s=1600 ft
t=√(s) /4
t=√(1600)/4
t=40/4
t=10 seconds
It would be -(-31) because a negative and negative is a positive
Step-by-step explanation:
Equation: 
First step:

Second step:

Third step:

Fourth step:

0.0044 as a percentage0.44%
Mean =12
Standard devation= 3.2863
variance???