The data in a number line
Notice that 3/4=0.75 (4 values), 1 (5 values), 1 1/4=1.25 (2 values), 1 1/2=1.5 (5 values), and 1 3/4=1.75 (2 values).
1) The minimum value in the data set is 3/4 while the maximum value is 1 3/4; therefore, the range is

The range is 1.
2) Adding the number in the data set

The answer to part 2) is 21.5 in.
3)

Thus, the answer to part 3) is 10.5 in