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Finding the Fourth Proportional to 679.78, 936.72 and 522.40

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Solution

The fourth proportional to 679.78, 936.72 and 522.40 is: 719.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.78 : 936.72 = 522.40 : x
  2. Step 2: Convert to fraction form
    679.78/936.72 = 522.40/x
  3. Step 3: Cross multiply
    679.78x = 936.72 × 522.40
  4. Step 4: Simplify right side
    679.78x = 489,342.53
  5. Step 5: Solve for x
    x = 489,342.53/679.78
  6. Step 6: Final answer
    x = 719.85

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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.