Question 1032910
The x-value for the vertex ( maximum in this case )
is given by the formula:
{{{ x[max] = -b/(2a) }}} when the equation has the form
{{{ P(x) = a*x^2 + b*x + c }}}
{{{ a = -22.5 }}}
{{{ b = 428 }}}
{{{ x[max] = -428 / ( 2*(-22.5) ) }}}
{{{ x[max] = 9.5111 }}}
The population is highest in June of 1999