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Finding the Fourth Proportional to 305.92, 421.85 and 231.40

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Solution

The fourth proportional to 305.92, 421.85 and 231.40 is: 319.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.92 : 421.85 = 231.40 : x
  2. Step 2: Convert to fraction form
    305.92/421.85 = 231.40/x
  3. Step 3: Cross multiply
    305.92x = 421.85 × 231.40
  4. Step 4: Simplify right side
    305.92x = 97,616.09
  5. Step 5: Solve for x
    x = 97,616.09/305.92
  6. Step 6: Final answer
    x = 319.09

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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.