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Finding the Fourth Proportional to 520.79, 781.57 and 419.30

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Solution

The fourth proportional to 520.79, 781.57 and 419.30 is: 629.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.79 : 781.57 = 419.30 : x
  2. Step 2: Convert to fraction form
    520.79/781.57 = 419.30/x
  3. Step 3: Cross multiply
    520.79x = 781.57 × 419.30
  4. Step 4: Simplify right side
    520.79x = 327,716.79
  5. Step 5: Solve for x
    x = 327,716.79/520.79
  6. Step 6: Final answer
    x = 629.26

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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.