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Finding the Fourth Proportional to 688.20, 949.30 and 455.40

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Solution

The fourth proportional to 688.20, 949.30 and 455.40 is: 628.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.20 : 949.30 = 455.40 : x
  2. Step 2: Convert to fraction form
    688.20/949.30 = 455.40/x
  3. Step 3: Cross multiply
    688.20x = 949.30 × 455.40
  4. Step 4: Simplify right side
    688.20x = 432,311.22
  5. Step 5: Solve for x
    x = 432,311.22/688.20
  6. Step 6: Final answer
    x = 628.18

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.