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Finding the Fourth Proportional to 312.95, 430.57 and 305.66

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Solution

The fourth proportional to 312.95, 430.57 and 305.66 is: 420.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.95 : 430.57 = 305.66 : x
  2. Step 2: Convert to fraction form
    312.95/430.57 = 305.66/x
  3. Step 3: Cross multiply
    312.95x = 430.57 × 305.66
  4. Step 4: Simplify right side
    312.95x = 131,608.03
  5. Step 5: Solve for x
    x = 131,608.03/312.95
  6. Step 6: Final answer
    x = 420.54

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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.