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Finding the Fourth Proportional to 813.93, 1,220.90 and 381.39

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Solution

The fourth proportional to 813.93, 1,220.90 and 381.39 is: 572.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.93 : 1,220.90 = 381.39 : x
  2. Step 2: Convert to fraction form
    813.93/1,220.90 = 381.39/x
  3. Step 3: Cross multiply
    813.93x = 1,220.90 × 381.39
  4. Step 4: Simplify right side
    813.93x = 465,639.05
  5. Step 5: Solve for x
    x = 465,639.05/813.93
  6. Step 6: Final answer
    x = 572.09

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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.