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Finding the Fourth Proportional to 647.05, 892.91 and 398.38

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Solution

The fourth proportional to 647.05, 892.91 and 398.38 is: 549.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.05 : 892.91 = 398.38 : x
  2. Step 2: Convert to fraction form
    647.05/892.91 = 398.38/x
  3. Step 3: Cross multiply
    647.05x = 892.91 × 398.38
  4. Step 4: Simplify right side
    647.05x = 355,716.25
  5. Step 5: Solve for x
    x = 355,716.25/647.05
  6. Step 6: Final answer
    x = 549.75

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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.