Question 688330
{{{f(t) = 440/(1+4.5*e^(-0.11*t))}}}


{{{f(19) = 440/(1+4.5*e^(-0.11*19))}}}


{{{f(19) = 440/(1+4.5*e^(-2.09))}}}


{{{f(19) = 440/(1+4.5*0.123687)}}}


{{{f(19) = 440/(1+0.5565915)}}}


{{{f(19) = 440/(1.5565915)}}}


{{{f(19) = 282.668895}}}


Round up to get 283. So there are roughly 283 butterflies, which means you are 100% correct.