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Finding the Fourth Proportional to 509.78, 764.40 and 278.12

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Solution

The fourth proportional to 509.78, 764.40 and 278.12 is: 417.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.78 : 764.40 = 278.12 : x
  2. Step 2: Convert to fraction form
    509.78/764.40 = 278.12/x
  3. Step 3: Cross multiply
    509.78x = 764.40 × 278.12
  4. Step 4: Simplify right side
    509.78x = 212,594.93
  5. Step 5: Solve for x
    x = 212,594.93/509.78
  6. Step 6: Final answer
    x = 417.03

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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.