Question #da231

1 Answer
Aug 27, 2017

#x=65#

Explanation:

The mean of a data set is the average of all of its elements.

#"mean" = "sum of all elements" / "number of elements"#

For instance, the mean of #10# and #20# would be #(10+20)/2 = 15#.

Similarly, the mean of #70, 62, 67,# and #x# is

#(70+62+67+x)/4#

We are told the mean is equal to #66#, so set the entire expression above equal to #66#. Now, solve for #x#.

#66 = (70+62+67+x)/4#

#66 * 4= 70+62+67+x#

#264 = 199 + x#

#x = 65#