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Finding the Fourth Proportional to 688.54, 1,028.02 and 646.85

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Solution

The fourth proportional to 688.54, 1,028.02 and 646.85 is: 965.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.54 : 1,028.02 = 646.85 : x
  2. Step 2: Convert to fraction form
    688.54/1,028.02 = 646.85/x
  3. Step 3: Cross multiply
    688.54x = 1,028.02 × 646.85
  4. Step 4: Simplify right side
    688.54x = 664,974.74
  5. Step 5: Solve for x
    x = 664,974.74/688.54
  6. Step 6: Final answer
    x = 965.78

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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.