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Finding the Fourth Proportional to 514.89, 772.23 and 428.78

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Solution

The fourth proportional to 514.89, 772.23 and 428.78 is: 643.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    514.89 : 772.23 = 428.78 : x
  2. Step 2: Convert to fraction form
    514.89/772.23 = 428.78/x
  3. Step 3: Cross multiply
    514.89x = 772.23 × 428.78
  4. Step 4: Simplify right side
    514.89x = 331,112.92
  5. Step 5: Solve for x
    x = 331,112.92/514.89
  6. Step 6: Final answer
    x = 643.08

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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.