Calculating Mass-Kepler's 3rd Law

[winterrose]

Okay, so I understand that a3/p2=M

I must be missing something though.

I know that (6x10^9)3 / (7.8x10^8)2 = 3.6x10^11 MSun

but I don't understand what step I'm missing. When I divide, I end up with 0.3550^12

what am I doing wrong?

Is my answer in kilograms, and do I have to convert it to MSun?

 

[tiny-tim]

welcome to pf!

hi winterrose! welcome to pf!

(try using the X² icon just above the Reply box )

… = 3.6x10^11 MSun

but I don't understand what step I'm missing. When I divide, I end up with 0.3550^12

they're (aproximately) the same, aren't they?