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Finding the Fourth Proportional to 648.98, 972.35 and 429.40

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Solution

The fourth proportional to 648.98, 972.35 and 429.40 is: 643.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.98 : 972.35 = 429.40 : x
  2. Step 2: Convert to fraction form
    648.98/972.35 = 429.40/x
  3. Step 3: Cross multiply
    648.98x = 972.35 × 429.40
  4. Step 4: Simplify right side
    648.98x = 417,520.08
  5. Step 5: Solve for x
    x = 417,520.08/648.98
  6. Step 6: Final answer
    x = 643.35

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.