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Finding the Fourth Proportional to 405.29, 559.56 and 311.87

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Solution

The fourth proportional to 405.29, 559.56 and 311.87 is: 430.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.29 : 559.56 = 311.87 : x
  2. Step 2: Convert to fraction form
    405.29/559.56 = 311.87/x
  3. Step 3: Cross multiply
    405.29x = 559.56 × 311.87
  4. Step 4: Simplify right side
    405.29x = 174,507.18
  5. Step 5: Solve for x
    x = 174,507.18/405.29
  6. Step 6: Final answer
    x = 430.58

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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.