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Finding the Fourth Proportional to 1,220.38, 1,830.78 and 398.56

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Solution

The fourth proportional to 1,220.38, 1,830.78 and 398.56 is: 597.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,220.38 : 1,830.78 = 398.56 : x
  2. Step 2: Convert to fraction form
    1,220.38/1,830.78 = 398.56/x
  3. Step 3: Cross multiply
    1,220.38x = 1,830.78 × 398.56
  4. Step 4: Simplify right side
    1,220.38x = 729,675.68
  5. Step 5: Solve for x
    x = 729,675.68/1,220.38
  6. Step 6: Final answer
    x = 597.91

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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.