First, we need to find the average of the smart TV price.
To do this, first add A,B, C and D together.
499 + 420 + 439.99 + 479.99 = 1838.98.
Because this is from 4 shops, we need to divide it by 4 to give the average price.
1838.98/4=459.745
Now that we have the average, we need to find out what 80% of it would be to see what Stella would set the price as.
459.745/100 (note: perCENT. How many years in a century? That's how you remember what to divide it by)
=4.59745
This needs to be multiplied by 80 (the answer asks for 80%) to give the answer.
4.59745x80=367.796 (remember to add the pounds unit, sorry don't know where it is on my keyboard)
hopefully this helps, let me know if you are still unsure of anything :)
