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Finding the Fourth Proportional to 502.08, 689.88 and 398.40

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Solution

The fourth proportional to 502.08, 689.88 and 398.40 is: 547.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    502.08 : 689.88 = 398.40 : x
  2. Step 2: Convert to fraction form
    502.08/689.88 = 398.40/x
  3. Step 3: Cross multiply
    502.08x = 689.88 × 398.40
  4. Step 4: Simplify right side
    502.08x = 274,848.19
  5. Step 5: Solve for x
    x = 274,848.19/502.08
  6. Step 6: Final answer
    x = 547.42

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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.