Based on your observation of the Tracker videos and the calculations of average vertical velocity and acceleration, Why do you think the vertical acceleration values are not equal to the theoretical acceleration due to gravity, -9.81 meters/second2?
What can you say about your earlier prediction about which ball will land first? If your hypothesis was wrong, can you propose an alternate rationale for the observed results?

15.3 cos 65 degrees trig

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =