SAT Practice Exam

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Statistics: Mean, Median, Mode

What is the mean, median, mode of (7,2,8,-4,7,8)

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Answer

Calculate Mean (Average) denoted as μ

μ  =	Sum of your number Set
	Total Numbers Entered

μ  =	ΣXi
	n

μ  =	7 + 2 + 8 - 4 + 7 + 8
	6

μ  =	28
	6

μ = 4.6667

Calculate the Median (Middle Value)
Since our number set contains 6 elements which is an even number, our median number is determined as follows:
Number Set = (n₁,n₂,n₃,n₄,n₅,n₆)
Median Number 1 = ½(n)
Median Number 1 = ½(6)
Median Number 1 = Number Set Entry 3

Median Number 2 = Median Number 1 + 1
Median Number 2 = Number Set Entry 3 + 1
Median Number 2 = Number Set Entry 4

For an even number set, we average the 2 median number entries:
Median = ½(n₃ + n₄)

Therefore, we sort our number set in ascending order and our median is the average of entry 3 and entry 4 of our number set highlighted in red:
(-4,2,7,7,8,8)
Median = ½(7 + 7)
Median = ½(14)
Median = 7

Calculate the Mode - Highest Frequency Number

The highest frequency of occurence in our number set is 2 times by the following numbers in green:
(-4,2,7,7,8,8)
Our mode is denoted as: 7 and 8
Mode = 7 and 8