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Finding the Fourth Proportional to 660.77, 911.63 and 398.69

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Solution

The fourth proportional to 660.77, 911.63 and 398.69 is: 550.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.77 : 911.63 = 398.69 : x
  2. Step 2: Convert to fraction form
    660.77/911.63 = 398.69/x
  3. Step 3: Cross multiply
    660.77x = 911.63 × 398.69
  4. Step 4: Simplify right side
    660.77x = 363,455.77
  5. Step 5: Solve for x
    x = 363,455.77/660.77
  6. Step 6: Final answer
    x = 550.05

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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.