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Finding the Fourth Proportional to 807.90, 1,212.08 and 418.12

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Solution

The fourth proportional to 807.90, 1,212.08 and 418.12 is: 627.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.90 : 1,212.08 = 418.12 : x
  2. Step 2: Convert to fraction form
    807.90/1,212.08 = 418.12/x
  3. Step 3: Cross multiply
    807.90x = 1,212.08 × 418.12
  4. Step 4: Simplify right side
    807.90x = 506,794.89
  5. Step 5: Solve for x
    x = 506,794.89/807.90
  6. Step 6: Final answer
    x = 627.30

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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.