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Finding the Fourth Proportional to 639.78, 956.33 and 556.89

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Solution

The fourth proportional to 639.78, 956.33 and 556.89 is: 832.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.78 : 956.33 = 556.89 : x
  2. Step 2: Convert to fraction form
    639.78/956.33 = 556.89/x
  3. Step 3: Cross multiply
    639.78x = 956.33 × 556.89
  4. Step 4: Simplify right side
    639.78x = 532,567.83
  5. Step 5: Solve for x
    x = 532,567.83/639.78
  6. Step 6: Final answer
    x = 832.42

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.