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Finding the Fourth Proportional to 305.10, 420.86 and 187.13

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Solution

The fourth proportional to 305.10, 420.86 and 187.13 is: 258.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.10 : 420.86 = 187.13 : x
  2. Step 2: Convert to fraction form
    305.10/420.86 = 187.13/x
  3. Step 3: Cross multiply
    305.10x = 420.86 × 187.13
  4. Step 4: Simplify right side
    305.10x = 78,755.53
  5. Step 5: Solve for x
    x = 78,755.53/305.10
  6. Step 6: Final answer
    x = 258.13

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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.