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Finding the Fourth Proportional to 305.10, 421.29 and 239.58

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Solution

The fourth proportional to 305.10, 421.29 and 239.58 is: 330.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.10 : 421.29 = 239.58 : x
  2. Step 2: Convert to fraction form
    305.10/421.29 = 239.58/x
  3. Step 3: Cross multiply
    305.10x = 421.29 × 239.58
  4. Step 4: Simplify right side
    305.10x = 100,932.66
  5. Step 5: Solve for x
    x = 100,932.66/305.10
  6. Step 6: Final answer
    x = 330.82

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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.