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Finding the Fourth Proportional to 647.15, 892.76 and 398.48

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Solution

The fourth proportional to 647.15, 892.76 and 398.48 is: 549.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.15 : 892.76 = 398.48 : x
  2. Step 2: Convert to fraction form
    647.15/892.76 = 398.48/x
  3. Step 3: Cross multiply
    647.15x = 892.76 × 398.48
  4. Step 4: Simplify right side
    647.15x = 355,740.55
  5. Step 5: Solve for x
    x = 355,740.55/647.15
  6. Step 6: Final answer
    x = 549.71

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.