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Finding the Fourth Proportional to 818.47, 1,225.65 and 427.09

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Solution

The fourth proportional to 818.47, 1,225.65 and 427.09 is: 639.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.47 : 1,225.65 = 427.09 : x
  2. Step 2: Convert to fraction form
    818.47/1,225.65 = 427.09/x
  3. Step 3: Cross multiply
    818.47x = 1,225.65 × 427.09
  4. Step 4: Simplify right side
    818.47x = 523,462.86
  5. Step 5: Solve for x
    x = 523,462.86/818.47
  6. Step 6: Final answer
    x = 639.56

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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.