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Finding the Fourth Proportional to 509.85, 764.09 and 278.40

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Solution

The fourth proportional to 509.85, 764.09 and 278.40 is: 417.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.85 : 764.09 = 278.40 : x
  2. Step 2: Convert to fraction form
    509.85/764.09 = 278.40/x
  3. Step 3: Cross multiply
    509.85x = 764.09 × 278.40
  4. Step 4: Simplify right side
    509.85x = 212,718.84
  5. Step 5: Solve for x
    x = 212,718.84/509.85
  6. Step 6: Final answer
    x = 417.22

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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.