Respuesta :

Why not write all of the numbers in decimal fraction form, to make them easier to compare?

68 2/3 = 68.666...
72 1/2 = 72.500
68 3/10 = 68.300
74 7/11 = 74.636...
68 1/2  = 68.500
550/8 = 68.750

Now ask yourself:  Which of the last four numbers is between 68.666.. and 72.500?
you can do this by converting all fractions to decimal form

68 2/3  = 68.66666...   72 1/2  = 72.5

68 3/10 = 68.3, 747/11 =  67.909, 68 1/2 = 68.5 and 550/8 =  68.75

so we see that 68.75  ( that is 550/8) is the correct option