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Finding the Fourth Proportional to 807.84, 1,211.80 and 345.84

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Solution

The fourth proportional to 807.84, 1,211.80 and 345.84 is: 518.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.84 : 1,211.80 = 345.84 : x
  2. Step 2: Convert to fraction form
    807.84/1,211.80 = 345.84/x
  3. Step 3: Cross multiply
    807.84x = 1,211.80 × 345.84
  4. Step 4: Simplify right side
    807.84x = 419,088.91
  5. Step 5: Solve for x
    x = 419,088.91/807.84
  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.