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Finding the Fourth Proportional to 520.46, 780.67 and 428.79

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Solution

The fourth proportional to 520.46, 780.67 and 428.79 is: 643.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.46 : 780.67 = 428.79 : x
  2. Step 2: Convert to fraction form
    520.46/780.67 = 428.79/x
  3. Step 3: Cross multiply
    520.46x = 780.67 × 428.79
  4. Step 4: Simplify right side
    520.46x = 334,743.49
  5. Step 5: Solve for x
    x = 334,743.49/520.46
  6. Step 6: Final answer
    x = 643.17

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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.