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Finding the Fourth Proportional to 1,212.30, 1,819.80 and 664.50

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Solution

The fourth proportional to 1,212.30, 1,819.80 and 664.50 is: 997.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,212.30 : 1,819.80 = 664.50 : x
  2. Step 2: Convert to fraction form
    1,212.30/1,819.80 = 664.50/x
  3. Step 3: Cross multiply
    1,212.30x = 1,819.80 × 664.50
  4. Step 4: Simplify right side
    1,212.30x = 1,209,257.10
  5. Step 5: Solve for x
    x = 1,209,257.10/1,212.30
  6. Step 6: Final answer
    x = 997.49

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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.