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Finding the Fourth Proportional to 628.40, 862.55 and 556.90

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Solution

The fourth proportional to 628.40, 862.55 and 556.90 is: 764.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.40 : 862.55 = 556.90 : x
  2. Step 2: Convert to fraction form
    628.40/862.55 = 556.90/x
  3. Step 3: Cross multiply
    628.40x = 862.55 × 556.90
  4. Step 4: Simplify right side
    628.40x = 480,351.24
  5. Step 5: Solve for x
    x = 480,351.24/628.40
  6. Step 6: Final answer
    x = 764.40

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.