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Finding the Fourth Proportional to 660.41, 911.33 and 398.42

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Solution

The fourth proportional to 660.41, 911.33 and 398.42 is: 549.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.41 : 911.33 = 398.42 : x
  2. Step 2: Convert to fraction form
    660.41/911.33 = 398.42/x
  3. Step 3: Cross multiply
    660.41x = 911.33 × 398.42
  4. Step 4: Simplify right side
    660.41x = 363,087.54
  5. Step 5: Solve for x
    x = 363,087.54/660.41
  6. Step 6: Final answer
    x = 549.80

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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.