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Finding the Fourth Proportional to 309, 426.30 and 221.80

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Solution

The fourth proportional to 309, 426.30 and 221.80 is: 306.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    309 : 426.30 = 221.80 : x
  2. Step 2: Convert to fraction form
    309/426.30 = 221.80/x
  3. Step 3: Cross multiply
    309x = 426.30 × 221.80
  4. Step 4: Simplify right side
    309x = 94,553.34
  5. Step 5: Solve for x
    x = 94,553.34/309
  6. Step 6: Final answer
    x = 306.00

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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.