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Finding the Fourth Proportional to 509.78, 703.53 and 288.78

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Solution

The fourth proportional to 509.78, 703.53 and 288.78 is: 398.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.78 : 703.53 = 288.78 : x
  2. Step 2: Convert to fraction form
    509.78/703.53 = 288.78/x
  3. Step 3: Cross multiply
    509.78x = 703.53 × 288.78
  4. Step 4: Simplify right side
    509.78x = 203,165.39
  5. Step 5: Solve for x
    x = 203,165.39/509.78
  6. Step 6: Final answer
    x = 398.54

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.