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Finding the Fourth Proportional to 805.32, 1,207.26 and 420.12

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Solution

The fourth proportional to 805.32, 1,207.26 and 420.12 is: 629.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.32 : 1,207.26 = 420.12 : x
  2. Step 2: Convert to fraction form
    805.32/1,207.26 = 420.12/x
  3. Step 3: Cross multiply
    805.32x = 1,207.26 × 420.12
  4. Step 4: Simplify right side
    805.32x = 507,194.07
  5. Step 5: Solve for x
    x = 507,194.07/805.32
  6. Step 6: Final answer
    x = 629.80

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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.