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Finding the Fourth Proportional to 258.21, 356.12 and 221.13

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Solution

The fourth proportional to 258.21, 356.12 and 221.13 is: 304.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.21 : 356.12 = 221.13 : x
  2. Step 2: Convert to fraction form
    258.21/356.12 = 221.13/x
  3. Step 3: Cross multiply
    258.21x = 356.12 × 221.13
  4. Step 4: Simplify right side
    258.21x = 78,747.71
  5. Step 5: Solve for x
    x = 78,747.71/258.21
  6. Step 6: Final answer
    x = 304.98

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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.