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Finding the Fourth Proportional to 520.54, 780.92 and 212.40

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Solution

The fourth proportional to 520.54, 780.92 and 212.40 is: 318.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.54 : 780.92 = 212.40 : x
  2. Step 2: Convert to fraction form
    520.54/780.92 = 212.40/x
  3. Step 3: Cross multiply
    520.54x = 780.92 × 212.40
  4. Step 4: Simplify right side
    520.54x = 165,863.50
  5. Step 5: Solve for x
    x = 165,863.50/520.54
  6. Step 6: Final answer
    x = 318.64

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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.