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Finding the Fourth Proportional to 643.17, 965.85 and 611.25

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Solution

The fourth proportional to 643.17, 965.85 and 611.25 is: 917.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.17 : 965.85 = 611.25 : x
  2. Step 2: Convert to fraction form
    643.17/965.85 = 611.25/x
  3. Step 3: Cross multiply
    643.17x = 965.85 × 611.25
  4. Step 4: Simplify right side
    643.17x = 590,375.81
  5. Step 5: Solve for x
    x = 590,375.81/643.17
  6. Step 6: Final answer
    x = 917.92

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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.