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Finding the Fourth Proportional to 405.65, 559.85 and 231

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Solution

The fourth proportional to 405.65, 559.85 and 231 is: 318.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.65 : 559.85 = 231 : x
  2. Step 2: Convert to fraction form
    405.65/559.85 = 231/x
  3. Step 3: Cross multiply
    405.65x = 559.85 × 231
  4. Step 4: Simplify right side
    405.65x = 129,324.20
  5. Step 5: Solve for x
    x = 129,324.20/405.65
  6. Step 6: Final answer
    x = 318.81

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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.