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Finding the Fourth Proportional to 647.20, 893.13 and 398.42

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Solution

The fourth proportional to 647.20, 893.13 and 398.42 is: 549.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.20 : 893.13 = 398.42 : x
  2. Step 2: Convert to fraction form
    647.20/893.13 = 398.42/x
  3. Step 3: Cross multiply
    647.20x = 893.13 × 398.42
  4. Step 4: Simplify right side
    647.20x = 355,840.85
  5. Step 5: Solve for x
    x = 355,840.85/647.20
  6. Step 6: Final answer
    x = 549.82

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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.