Answer:

Step-by-step explanation:
this goes with BODMAS .so it means bracket of divison,multiplication ,addition and subtraction
this means that you would have to solve the one in the bracket first before you'll continue with the rest,that is the subtraction.
Well let’s find the actually mean
First we add up all the numbers
87+46+90+78+89 = 390
Next we divide 390 by how many numbers there are.
390/5 = 78
Therefore the mean is 78
Emi failed to find the difference