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Finding the Fourth Proportional to 305.16, 420.72 and 255.96

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Solution

The fourth proportional to 305.16, 420.72 and 255.96 is: 352.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.16 : 420.72 = 255.96 : x
  2. Step 2: Convert to fraction form
    305.16/420.72 = 255.96/x
  3. Step 3: Cross multiply
    305.16x = 420.72 × 255.96
  4. Step 4: Simplify right side
    305.16x = 107,687.49
  5. Step 5: Solve for x
    x = 107,687.49/305.16
  6. Step 6: Final answer
    x = 352.89

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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.