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Finding the Fourth Proportional to 312.96, 430.56 and 305.66

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Solution

The fourth proportional to 312.96, 430.56 and 305.66 is: 420.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.96 : 430.56 = 305.66 : x
  2. Step 2: Convert to fraction form
    312.96/430.56 = 305.66/x
  3. Step 3: Cross multiply
    312.96x = 430.56 × 305.66
  4. Step 4: Simplify right side
    312.96x = 131,604.97
  5. Step 5: Solve for x
    x = 131,604.97/312.96
  6. Step 6: Final answer
    x = 420.52

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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.