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Finding the Fourth Proportional to 305.65, 421.64 and 231.85

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Solution

The fourth proportional to 305.65, 421.64 and 231.85 is: 319.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.65 : 421.64 = 231.85 : x
  2. Step 2: Convert to fraction form
    305.65/421.64 = 231.85/x
  3. Step 3: Cross multiply
    305.65x = 421.64 × 231.85
  4. Step 4: Simplify right side
    305.65x = 97,753.97
  5. Step 5: Solve for x
    x = 97,753.97/305.65
  6. Step 6: Final answer
    x = 319.82

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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.