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Finding the Fourth Proportional to 686.55, 1,027.40 and 645.06

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Solution

The fourth proportional to 686.55, 1,027.40 and 645.06 is: 965.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.55 : 1,027.40 = 645.06 : x
  2. Step 2: Convert to fraction form
    686.55/1,027.40 = 645.06/x
  3. Step 3: Cross multiply
    686.55x = 1,027.40 × 645.06
  4. Step 4: Simplify right side
    686.55x = 662,731.42
  5. Step 5: Solve for x
    x = 662,731.42/686.55
  6. Step 6: Final answer
    x = 965.31

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.