Assuming you mean the arithmetic mean, it is 80.
The variance of 73 72 67 74 78 84 79 71 76 76 79 81 75 80 78 76 78 = 16.8456
There are an infinite number of sets with mean 80. Here are some: {80, 80, 80}, {80, 80, 80, 80, 80, 80} {79, 80, 81}, {79, 79, 80, 81, 81}, {79, 79, 80, 82} (1, 80, 159}, {-40, 200} To produce a set of n numbers with mean 80, start with any set of n-1 numbers. Suppose their sum is S. Then add the number 80*n-S to the set. You will now have n numbers whose sum is S+80*n-S = 80*n So the mean of this set is 80.
71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100! :)
60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87
Assuming you mean the arithmetic mean, it is 80.
The variance of 73 72 67 74 78 84 79 71 76 76 79 81 75 80 78 76 78 = 16.8456
83
The answer is 711. Simply add up all of the numbers arithmetically like you would for two plus two. To make sure the answer is correct, check your work using a calculator.
81
765
the mean is 79.75
78
80+1 = 81
237
There are infinitely many. Involving integers (whole numbers) there are: 0 + 80, 1 + 79, 2 + 78, .... 78 + 2, 79 + 1, 80 + 0, 81 + -1, 82 + -2, ..... When you include non-integers there are: ½ + 79½, 1½ + 78½, ... 1.1 + 78.9, 1.2 + 78.8, .... 3.1 + 76.9, 3.14 + 76.86, 3.141 + 76.859, 3.1415 + 76.8585, 3.14159 + 76.85841, ...., π + (80 - π)
79, -79