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Finding the Fourth Proportional to 312.12, 430.38 and 201.45

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Solution

The fourth proportional to 312.12, 430.38 and 201.45 is: 277.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.12 : 430.38 = 201.45 : x
  2. Step 2: Convert to fraction form
    312.12/430.38 = 201.45/x
  3. Step 3: Cross multiply
    312.12x = 430.38 × 201.45
  4. Step 4: Simplify right side
    312.12x = 86,700.05
  5. Step 5: Solve for x
    x = 86,700.05/312.12
  6. Step 6: Final answer
    x = 277.78

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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.