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Finding the Fourth Proportional to 509.60, 764.68 and 221

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Solution

The fourth proportional to 509.60, 764.68 and 221 is: 331.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.60 : 764.68 = 221 : x
  2. Step 2: Convert to fraction form
    509.60/764.68 = 221/x
  3. Step 3: Cross multiply
    509.60x = 764.68 × 221
  4. Step 4: Simplify right side
    509.60x = 168,994.28
  5. Step 5: Solve for x
    x = 168,994.28/509.60
  6. Step 6: Final answer
    x = 331.62

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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.