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Finding the Fourth Proportional to 309.79, 427.71 and 238.76

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Solution

The fourth proportional to 309.79, 427.71 and 238.76 is: 329.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.79 : 427.71 = 238.76 : x
  2. Step 2: Convert to fraction form
    309.79/427.71 = 238.76/x
  3. Step 3: Cross multiply
    309.79x = 427.71 × 238.76
  4. Step 4: Simplify right side
    309.79x = 102,121.46
  5. Step 5: Solve for x
    x = 102,121.46/309.79
  6. Step 6: Final answer
    x = 329.65

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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.