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Finding the Fourth Proportional to 305.07, 420.91 and 180.78

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Solution

The fourth proportional to 305.07, 420.91 and 180.78 is: 249.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.07 : 420.91 = 180.78 : x
  2. Step 2: Convert to fraction form
    305.07/420.91 = 180.78/x
  3. Step 3: Cross multiply
    305.07x = 420.91 × 180.78
  4. Step 4: Simplify right side
    305.07x = 76,092.11
  5. Step 5: Solve for x
    x = 76,092.11/305.07
  6. Step 6: Final answer
    x = 249.43

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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.