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Finding the Fourth Proportional to 930.39, 1,395.80 and 345.80

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Solution

The fourth proportional to 930.39, 1,395.80 and 345.80 is: 518.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    930.39 : 1,395.80 = 345.80 : x
  2. Step 2: Convert to fraction form
    930.39/1,395.80 = 345.80/x
  3. Step 3: Cross multiply
    930.39x = 1,395.80 × 345.80
  4. Step 4: Simplify right side
    930.39x = 482,665.91
  5. Step 5: Solve for x
    x = 482,665.91/930.39
  6. Step 6: Final answer
    x = 518.78

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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.