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Finding the Fourth Proportional to 807.89, 1,211.90 and 345.68

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Solution

The fourth proportional to 807.89, 1,211.90 and 345.68 is: 518.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.89 : 1,211.90 = 345.68 : x
  2. Step 2: Convert to fraction form
    807.89/1,211.90 = 345.68/x
  3. Step 3: Cross multiply
    807.89x = 1,211.90 × 345.68
  4. Step 4: Simplify right side
    807.89x = 418,929.59
  5. Step 5: Solve for x
    x = 418,929.59/807.89
  6. Step 6: Final answer
    x = 518.55

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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.