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Finding the Fourth Proportional to 643.38, 965.85 and 611.07

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Solution

The fourth proportional to 643.38, 965.85 and 611.07 is: 917.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.38 : 965.85 = 611.07 : x
  2. Step 2: Convert to fraction form
    643.38/965.85 = 611.07/x
  3. Step 3: Cross multiply
    643.38x = 965.85 × 611.07
  4. Step 4: Simplify right side
    643.38x = 590,201.96
  5. Step 5: Solve for x
    x = 590,201.96/643.38
  6. Step 6: Final answer
    x = 917.35

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.