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Finding the Fourth Proportional to 398.30, 549.61 and 221.26

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Solution

The fourth proportional to 398.30, 549.61 and 221.26 is: 305.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.30 : 549.61 = 221.26 : x
  2. Step 2: Convert to fraction form
    398.30/549.61 = 221.26/x
  3. Step 3: Cross multiply
    398.30x = 549.61 × 221.26
  4. Step 4: Simplify right side
    398.30x = 121,606.71
  5. Step 5: Solve for x
    x = 121,606.71/398.30
  6. Step 6: Final answer
    x = 305.31

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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.