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Finding the Fourth Proportional to 515.19, 771.89 and 429.08

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Solution

The fourth proportional to 515.19, 771.89 and 429.08 is: 642.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.19 : 771.89 = 429.08 : x
  2. Step 2: Convert to fraction form
    515.19/771.89 = 429.08/x
  3. Step 3: Cross multiply
    515.19x = 771.89 × 429.08
  4. Step 4: Simplify right side
    515.19x = 331,196.56
  5. Step 5: Solve for x
    x = 331,196.56/515.19
  6. Step 6: Final answer
    x = 642.86

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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.