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Finding the Fourth Proportional to 398.11, 549.39 and 221.10

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Solution

The fourth proportional to 398.11, 549.39 and 221.10 is: 305.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.11 : 549.39 = 221.10 : x
  2. Step 2: Convert to fraction form
    398.11/549.39 = 221.10/x
  3. Step 3: Cross multiply
    398.11x = 549.39 × 221.10
  4. Step 4: Simplify right side
    398.11x = 121,466.28
  5. Step 5: Solve for x
    x = 121,466.28/398.11
  6. Step 6: Final answer
    x = 305.11

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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.