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Finding the Fourth Proportional to 312.17, 430.72 and 187.81

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Solution

The fourth proportional to 312.17, 430.72 and 187.81 is: 259.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.17 : 430.72 = 187.81 : x
  2. Step 2: Convert to fraction form
    312.17/430.72 = 187.81/x
  3. Step 3: Cross multiply
    312.17x = 430.72 × 187.81
  4. Step 4: Simplify right side
    312.17x = 80,890.43
  5. Step 5: Solve for x
    x = 80,890.43/312.17
  6. Step 6: Final answer
    x = 259.12

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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.