what is the mean, median, mode, variance and standard deviation of.....?

Question

what is the mean, median, mode, variance and standard deviation of {4,6,7,5,9,4,3,4}

Answer 1

The mode is 4, because there are more of them than any other.

Answer 2

Mean= (4+6+7+5+9+4+3+4)/8 = 5.25
Median is the middle number when numbers are in order so {3, 4, 4, 4, 5, 6, 7, 9} so the middle two numbers are 4 and 5 so the median is 4.5 (the average of the two middle numbers).
Mode is the number that appears most often so this is 4.
Variance is when you sum up the square of the differences from the mean and divide by the number of itmesso (3-5.25)^2 + (4-5.25)^2 + (4-5.25)^2 + (4-4.25)^2 + (5-5.25)^2 + (6-5.25)^2 + (7-5.25)^2 + (9-5.25)^2 = 228.0676. Now divide by 8 so variance = 28.5
Standard deviation is the square root of variance so st. dev. = sqrt(28.5) = 5.34