How Many Tennis Ball Can Fit in a Boeing 737?

Assume that in a Boeing 737 there are 6 seats in one row and a walking area in between. Each seat is designed for one person with some space for the handles. Assume that the width of 1 seat is 0.5m.Thus for 6 seats 6*0.5=3.0m. Assume the walkway passage to be 1.5m wide. 

Thus total width of the plane = 3.0+1.5+0.5(buffer) = 5.0m

And Assuming there are 70rows in a plane each at a meter space. 5m ahead of all the rows and 5m behind all the rows

Thus height of the plane = 80m

Calculating for the tennis ball

Tennis ball is a sphere with radius of approx 3 cms = 0.03 m

Volume of a tennis ball = 4/3(pi r^3) = 1.33*0.000027*pi

think of a boeing 747 as a cylinder with length (height) = approx 80 m and radius = 5 m

volume of a boeing 747 = pi*(r^2)*h = 25*80*pi

# of tennis balls that fit into a boeing 747 ~ (25*80)/(1.33*0.000027) ~ 6,000,000 tennis balls

The entirety of the volume of the cabin can’t be perfectly taken up by spherical tennis balls, the random packing efficiency of tennis balls is around 64%, so multiply 6,000,000 by .64 to get 3,840,000