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Finding the Fourth Proportional to 624.39, 861.54 and 388.40

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Solution

The fourth proportional to 624.39, 861.54 and 388.40 is: 535.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    624.39 : 861.54 = 388.40 : x
  2. Step 2: Convert to fraction form
    624.39/861.54 = 388.40/x
  3. Step 3: Cross multiply
    624.39x = 861.54 × 388.40
  4. Step 4: Simplify right side
    624.39x = 334,622.14
  5. Step 5: Solve for x
    x = 334,622.14/624.39
  6. Step 6: Final answer
    x = 535.92

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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.