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Finding the Fourth Proportional to 312.32, 431.98 and 279.56

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Solution

The fourth proportional to 312.32, 431.98 and 279.56 is: 386.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.32 : 431.98 = 279.56 : x
  2. Step 2: Convert to fraction form
    312.32/431.98 = 279.56/x
  3. Step 3: Cross multiply
    312.32x = 431.98 × 279.56
  4. Step 4: Simplify right side
    312.32x = 120,764.33
  5. Step 5: Solve for x
    x = 120,764.33/312.32
  6. Step 6: Final answer
    x = 386.67

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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.