Problem solving with the Mean

Maths

The mean of these set of numbers 1, 2, 3, 6 is...

The number four is added to the set of numbers above. What happens to the mean?

In the first 6 tests he takes, Jake scores a mean of 60 marks. In the final 4 tests, he scores a mean of 70 marks. What is his overall mean?

What is the mean of the following group of numbers? 2, 2, 4, 6, 6

What is the mean of the following group of numbers? 0, 0, 1, 1, 2, 2, 5, 5

A set of 5 numbers is 3, 7, 8, 10, x (where x is a missing number). The mean of these 5 numbers is 6. What is the value of x?