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Finding the Fourth Proportional to 684.85, 945.10 and 390.12

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Solution

The fourth proportional to 684.85, 945.10 and 390.12 is: 538.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.85 : 945.10 = 390.12 : x
  2. Step 2: Convert to fraction form
    684.85/945.10 = 390.12/x
  3. Step 3: Cross multiply
    684.85x = 945.10 × 390.12
  4. Step 4: Simplify right side
    684.85x = 368,702.90
  5. Step 5: Solve for x
    x = 368,702.90/684.85
  6. Step 6: Final answer
    x = 538.37

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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.