1.What is x if the mean of the numbers 4,5,x,8,9 and 3 is 6? 2.what is the median if the mean of 10,8,7,12,x,6,10 and 4 is 8?

1) ##x = 7##. 2) Median = ##7.5##

Explanation:

Recall that the arithmetic mean ##bar x## of a data set may be determined as follows:

##bar x = sum_(i=1)^n x_i/n##. where n = number of numbers you adding up and ##x##= the number

Thus, for our initial data set:

##6 = (4+5+x+8+9+3)/6 -> 36 = 29 + x -> x = 7## (6x6=36)

For our second data set:

##8 = (10 + 8 + 7 + 12 + 6 + 10 + 4 + x)/8 -> 64 = 57 + x -> x = 7## (8x8 = 64)

However, we are not looking for ##x## in the second problem. We are looking for the median. Recall that the median is simply the value in the data set which separates the upper half of the data from the lower half. In this case, since we have an even number of values, our median will be the mean of the two middle numbers when the data is listed in ascending or descending numerical order.

##4, 6, 7, **7, 8**, 10, 10, 12##

Our middle values are 7 and 8. The arithmetic mean between the two would be ##(7+8)/2##, or ##7.5##.