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Finding the Fourth Proportional to 405.72, 559.71 and 312.30

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Solution

The fourth proportional to 405.72, 559.71 and 312.30 is: 430.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.72 : 559.71 = 312.30 : x
  2. Step 2: Convert to fraction form
    405.72/559.71 = 312.30/x
  3. Step 3: Cross multiply
    405.72x = 559.71 × 312.30
  4. Step 4: Simplify right side
    405.72x = 174,797.43
  5. Step 5: Solve for x
    x = 174,797.43/405.72
  6. Step 6: Final answer
    x = 430.83

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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.