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Finding the Fourth Proportional to 398.13, 549.42 and 221.10

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Solution

The fourth proportional to 398.13, 549.42 and 221.10 is: 305.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.13 : 549.42 = 221.10 : x
  2. Step 2: Convert to fraction form
    398.13/549.42 = 221.10/x
  3. Step 3: Cross multiply
    398.13x = 549.42 × 221.10
  4. Step 4: Simplify right side
    398.13x = 121,476.76
  5. Step 5: Solve for x
    x = 121,476.76/398.13
  6. Step 6: Final answer
    x = 305.12

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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.