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Finding the Fourth Proportional to 520.28, 780.78 and 383.68

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Solution

The fourth proportional to 520.28, 780.78 and 383.68 is: 575.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.28 : 780.78 = 383.68 : x
  2. Step 2: Convert to fraction form
    520.28/780.78 = 383.68/x
  3. Step 3: Cross multiply
    520.28x = 780.78 × 383.68
  4. Step 4: Simplify right side
    520.28x = 299,565.77
  5. Step 5: Solve for x
    x = 299,565.77/520.28
  6. Step 6: Final answer
    x = 575.78

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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.