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Finding the Fourth Proportional to 859.91, 1,289.21 and 427.37

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Solution

The fourth proportional to 859.91, 1,289.21 and 427.37 is: 640.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.91 : 1,289.21 = 427.37 : x
  2. Step 2: Convert to fraction form
    859.91/1,289.21 = 427.37/x
  3. Step 3: Cross multiply
    859.91x = 1,289.21 × 427.37
  4. Step 4: Simplify right side
    859.91x = 550,961.09
  5. Step 5: Solve for x
    x = 550,961.09/859.91
  6. Step 6: Final answer
    x = 640.72

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.