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Finding the Fourth Proportional to 660.31, 911.37 and 398.32

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Solution

The fourth proportional to 660.31, 911.37 and 398.32 is: 549.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.31 : 911.37 = 398.32 : x
  2. Step 2: Convert to fraction form
    660.31/911.37 = 398.32/x
  3. Step 3: Cross multiply
    660.31x = 911.37 × 398.32
  4. Step 4: Simplify right side
    660.31x = 363,016.90
  5. Step 5: Solve for x
    x = 363,016.90/660.31
  6. Step 6: Final answer
    x = 549.77

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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.