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Finding the Fourth Proportional to 520.34, 780.78 and 289.43

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Solution

The fourth proportional to 520.34, 780.78 and 289.43 is: 434.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.34 : 780.78 = 289.43 : x
  2. Step 2: Convert to fraction form
    520.34/780.78 = 289.43/x
  3. Step 3: Cross multiply
    520.34x = 780.78 × 289.43
  4. Step 4: Simplify right side
    520.34x = 225,981.16
  5. Step 5: Solve for x
    x = 225,981.16/520.34
  6. Step 6: Final answer
    x = 434.30

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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.