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Finding the Fourth Proportional to 808.80, 1,213.16 and 418.80

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Solution

The fourth proportional to 808.80, 1,213.16 and 418.80 is: 628.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.80 : 1,213.16 = 418.80 : x
  2. Step 2: Convert to fraction form
    808.80/1,213.16 = 418.80/x
  3. Step 3: Cross multiply
    808.80x = 1,213.16 × 418.80
  4. Step 4: Simplify right side
    808.80x = 508,071.41
  5. Step 5: Solve for x
    x = 508,071.41/808.80
  6. Step 6: Final answer
    x = 628.18

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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.