The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown". In x + 2 = 7, x is a variable, but we can work out its value if we try! A variable doesn't have to be "x", it could be "y", "w" or any letter, name or symbol.
The mean is 7.5 you add up all the numbers and then divide by the amount of numbers there is
Ok, I'm not giving you the answer. Instead, I'm going to give you the way to solve it. Then, you can do it yourself, message it to me, and I will check it.
Do .11 x 25. Remember to add the decimal back in.