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Finding the Fourth Proportional to 808.68, 1,213.38 and 438.60

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Solution

The fourth proportional to 808.68, 1,213.38 and 438.60 is: 658.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.68 : 1,213.38 = 438.60 : x
  2. Step 2: Convert to fraction form
    808.68/1,213.38 = 438.60/x
  3. Step 3: Cross multiply
    808.68x = 1,213.38 × 438.60
  4. Step 4: Simplify right side
    808.68x = 532,188.47
  5. Step 5: Solve for x
    x = 532,188.47/808.68
  6. Step 6: Final answer
    x = 658.10

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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.