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Finding the Fourth Proportional to 520.89, 780.60 and 260.64

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Solution

The fourth proportional to 520.89, 780.60 and 260.64 is: 390.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.89 : 780.60 = 260.64 : x
  2. Step 2: Convert to fraction form
    520.89/780.60 = 260.64/x
  3. Step 3: Cross multiply
    520.89x = 780.60 × 260.64
  4. Step 4: Simplify right side
    520.89x = 203,455.58
  5. Step 5: Solve for x
    x = 203,455.58/520.89
  6. Step 6: Final answer
    x = 390.59

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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.