Answer:
1) Mean = 6.28
2) Median = 7
3) Mode = 8
4) Range = 6
Step-by-step explanation:
We need to find Mean, Median, Mode and Range of data given in tables.
1) Mean
The formula used to calculate mean is: 
The data given is: 3, 3, 4, 4, 4, 5, 5, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 9, 9
Sum of all data points = 132
Number of data points = 21
Finding mean:

So, Mean = 6.28
2) Median
The formula used to calculate median is:
because we have n = odd
Number of data points n = 21
Putting values and finding the position of median term

So, in the given data : 3, 3, 4, 4, 4, 5, 5, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 9, 9
The 11 th term is 7
So, Median = 7
3) Mode
The mode is the most repetitive value of data set.
In the given data set: 3, 3, 4, 4, 4, 5, 5, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 9, 9
The most repetitive value is 8
So, Mode = 8
4) Range
The range can be calculated using formula: 
In the given data set: 3, 3, 4, 4, 4, 5, 5, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 9, 9
Maximum value = 9
Minimum value = 3
So, the range is:

So, Range = 6