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Finding the Fourth Proportional to 312.89, 431.79 and 188.55

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Solution

The fourth proportional to 312.89, 431.79 and 188.55 is: 260.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.89 : 431.79 = 188.55 : x
  2. Step 2: Convert to fraction form
    312.89/431.79 = 188.55/x
  3. Step 3: Cross multiply
    312.89x = 431.79 × 188.55
  4. Step 4: Simplify right side
    312.89x = 81,414.14
  5. Step 5: Solve for x
    x = 81,414.14/312.89
  6. Step 6: Final answer
    x = 260.20

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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.