the mean = (sum of the data ) / (number of data)
sum of the data = 86+91+94+86+88+86+74+66+74+73+68 = 886
number of data = 11
Hence,
mean = 886 / 11 = 80.5
b) To get the median, first we arrange the numbers in ascending order
66, 68, 73, 74, 74, 86, 86, 86, 88, 91, 94
The number of data is 11
Therefore the median is the 11 / 2 = 5.5th data
Counting from the left of the rearranged data set, we get 86
Hence, median = 86
c) mode is the number with the highest frequency.
From the rearranged data set, we get mode to be 86
mode = 86
d) Range = the highest - the lowest
the highest = 94,
the lowest = 66
Therefore
range = 28