Question 770794
{{{Mean=Sum/Number of terms}}}
{{{90=(90+85+x+95+90+100+90+100)/8}}}
{{{90=(x+650)/8}}}
{{{90*8=x+650}}}
{{{720=x+650}}}
{{{720-650=x}}}
{{{70=x}}}
{{{x=70}}}