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Finding the Fourth Proportional to 808.32, 1,213.20 and 645.60

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Solution

The fourth proportional to 808.32, 1,213.20 and 645.60 is: 968.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.32 : 1,213.20 = 645.60 : x
  2. Step 2: Convert to fraction form
    808.32/1,213.20 = 645.60/x
  3. Step 3: Cross multiply
    808.32x = 1,213.20 × 645.60
  4. Step 4: Simplify right side
    808.32x = 783,241.92
  5. Step 5: Solve for x
    x = 783,241.92/808.32
  6. Step 6: Final answer
    x = 968.98

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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.