250/195=(approximately) 1.2820512820512820512820512820513
The average of a set of numbers is their sum divided by how many there are. So, the average here is (250 + 310 + 275 + 195) / 4 and you can work that out.
195
195
195
195
2.6
250*78/100=195
195
27.8571
2.1196
195 divided by 6 is 32.5
32.5