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Finding the Fourth Proportional to 398.40, 549.82 and 221.37

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Solution

The fourth proportional to 398.40, 549.82 and 221.37 is: 305.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.40 : 549.82 = 221.37 : x
  2. Step 2: Convert to fraction form
    398.40/549.82 = 221.37/x
  3. Step 3: Cross multiply
    398.40x = 549.82 × 221.37
  4. Step 4: Simplify right side
    398.40x = 121,713.65
  5. Step 5: Solve for x
    x = 121,713.65/398.40
  6. Step 6: Final answer
    x = 305.51

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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.