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Finding the Fourth Proportional to 485.08, 669.56 and 398.68

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Solution

The fourth proportional to 485.08, 669.56 and 398.68 is: 550.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.08 : 669.56 = 398.68 : x
  2. Step 2: Convert to fraction form
    485.08/669.56 = 398.68/x
  3. Step 3: Cross multiply
    485.08x = 669.56 × 398.68
  4. Step 4: Simplify right side
    485.08x = 266,940.18
  5. Step 5: Solve for x
    x = 266,940.18/485.08
  6. Step 6: Final answer
    x = 550.30

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.