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Finding the Fourth Proportional to 859.96, 1,289.30 and 427.42

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Solution

The fourth proportional to 859.96, 1,289.30 and 427.42 is: 640.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.96 : 1,289.30 = 427.42 : x
  2. Step 2: Convert to fraction form
    859.96/1,289.30 = 427.42/x
  3. Step 3: Cross multiply
    859.96x = 1,289.30 × 427.42
  4. Step 4: Simplify right side
    859.96x = 551,072.61
  5. Step 5: Solve for x
    x = 551,072.61/859.96
  6. Step 6: Final answer
    x = 640.81

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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.