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Finding the Fourth Proportional to 305.47, 421.09 and 239.86

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Solution

The fourth proportional to 305.47, 421.09 and 239.86 is: 330.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.47 : 421.09 = 239.86 : x
  2. Step 2: Convert to fraction form
    305.47/421.09 = 239.86/x
  3. Step 3: Cross multiply
    305.47x = 421.09 × 239.86
  4. Step 4: Simplify right side
    305.47x = 101,002.65
  5. Step 5: Solve for x
    x = 101,002.65/305.47
  6. Step 6: Final answer
    x = 330.65

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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.