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Finding the Fourth Proportional to 806.60, 1,207.74 and 421.04

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Solution

The fourth proportional to 806.60, 1,207.74 and 421.04 is: 630.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.60 : 1,207.74 = 421.04 : x
  2. Step 2: Convert to fraction form
    806.60/1,207.74 = 421.04/x
  3. Step 3: Cross multiply
    806.60x = 1,207.74 × 421.04
  4. Step 4: Simplify right side
    806.60x = 508,506.85
  5. Step 5: Solve for x
    x = 508,506.85/806.60
  6. Step 6: Final answer
    x = 630.43

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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.