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Finding the Fourth Proportional to 520.09, 780.27 and 427.70

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Solution

The fourth proportional to 520.09, 780.27 and 427.70 is: 641.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.09 : 780.27 = 427.70 : x
  2. Step 2: Convert to fraction form
    520.09/780.27 = 427.70/x
  3. Step 3: Cross multiply
    520.09x = 780.27 × 427.70
  4. Step 4: Simplify right side
    520.09x = 333,718.55
  5. Step 5: Solve for x
    x = 333,718.55/520.09
  6. Step 6: Final answer
    x = 641.65

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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.