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Finding the Fourth Proportional to 678.17, 1,010.68 and 661.77

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Solution

The fourth proportional to 678.17, 1,010.68 and 661.77 is: 986.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.17 : 1,010.68 = 661.77 : x
  2. Step 2: Convert to fraction form
    678.17/1,010.68 = 661.77/x
  3. Step 3: Cross multiply
    678.17x = 1,010.68 × 661.77
  4. Step 4: Simplify right side
    678.17x = 668,836.05
  5. Step 5: Solve for x
    x = 668,836.05/678.17
  6. Step 6: Final answer
    x = 986.23

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.