Weare asked for the RATE at which the runner jogged. So, we need to perform the division (quotient) between the number of miles covered over the number of hours.
To facilitate the calculations we write the mixed numbers in fraction form:
6 3/4 miles = (24 + 3)/4 = 27/4 miles
1 1/2 hours = (2 + 1 ) / 2 = 3/2 hours.
So we need to do the divisionof two fractions:
27/4 miles divided by 3/2 hours
e recall that divisions of fractions can be easily calculated expressing them as the product of the first one multiplied by the reciprocal (inverted) of the second fraction:
27/4 * 2/3 = 54/12 = 9/2 miles per hour = 4.5 miles per hour (if your teacher wants the answer in decimal form)
If your teacher wants the answer in "mixed number form" you give 9/2 in mixed number: 4 1/2 miles per hour.