30 + 90 = 120
The mean is when you find the average of a set of numbers by adding them together and dividing the sum by how many numbers were in the set. Your set of numbers were 75, 89, and 30. The mean of these numbers would be 64.66. Since the 6 is ongoing you would round it and it would end up as 64.7. In some cases though, you might need to round it to the whole number. If so the mean would be 65.
89 rounds to 100.
Look at the digit in the ones position. That is the 9. A 9 will round the number up, so 89 will round up to 90.
1 and 89, -1 and -89
They are: 83 89 and 97
There are no prime numbers between 89 and 97.
what number goes in 89
They are: 1*89*1 = 89
89 is a prime number, so the only two numbers that you can multiply together to get a product of 89 are 1 and itself.
89
90.