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Finding the Fourth Proportional to 486.05, 669.60 and 398.57

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Solution

The fourth proportional to 486.05, 669.60 and 398.57 is: 549.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.05 : 669.60 = 398.57 : x
  2. Step 2: Convert to fraction form
    486.05/669.60 = 398.57/x
  3. Step 3: Cross multiply
    486.05x = 669.60 × 398.57
  4. Step 4: Simplify right side
    486.05x = 266,879.12
  5. Step 5: Solve for x
    x = 266,879.12/486.05
  6. Step 6: Final answer
    x = 549.08

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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.