Answer :
[tex]the\ data:\\\\51;\ 75;\ 79;\ \underline{81;\ 89};\ 90;\ 96;\ 98\\\\Median=\frac{81+89}{2}=\frac{170}{2}=\boxed{85}\\\\NO\ Mode\ because\ each\ number\ appears\ only\ once\\\\Answer:\boxed{C}[/tex]
You would add all the terms together and then divide to get the mean which is 51+75+79+81+89+90+96+98=584/8=73 and there is no mode.