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Finding the Fourth Proportional to 309.78, 427.29 and 226.71

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Solution

The fourth proportional to 309.78, 427.29 and 226.71 is: 312.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.78 : 427.29 = 226.71 : x
  2. Step 2: Convert to fraction form
    309.78/427.29 = 226.71/x
  3. Step 3: Cross multiply
    309.78x = 427.29 × 226.71
  4. Step 4: Simplify right side
    309.78x = 96,870.92
  5. Step 5: Solve for x
    x = 96,870.92/309.78
  6. Step 6: Final answer
    x = 312.71

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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.