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Finding the Fourth Proportional to 661.02, 911.79 and 398.97

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Solution

The fourth proportional to 661.02, 911.79 and 398.97 is: 550.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.02 : 911.79 = 398.97 : x
  2. Step 2: Convert to fraction form
    661.02/911.79 = 398.97/x
  3. Step 3: Cross multiply
    661.02x = 911.79 × 398.97
  4. Step 4: Simplify right side
    661.02x = 363,776.86
  5. Step 5: Solve for x
    x = 363,776.86/661.02
  6. Step 6: Final answer
    x = 550.33

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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.