Final answer:
To complete the rate table, use the given proportion 1/7 = 3/21. Solve for the variables a, b, and c in the second column by cross multiplying. The completed rate table should have values of 21, 105, and 105 for a, b, and c respectively.
Step-by-step explanation:
To complete the rate table, we can use the given proportion 1/7 = 3/21. We need to find the values of the variables a, b, and c in the second column. We can solve for a by cross multiplying: 1 * a = 7 * 3. Therefore, a = 21.
Similarly, we can solve for b and c. To find b, we use 1 * b = 7 * 15, which gives us b = 105. And to find c, we use 4 * c = 21 * 15, which gives us c = 105.
The completed rate table is as follows:
MilesMinutes174217632110515105