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Finding the Fourth Proportional to 643.59, 892.26 and 621.05

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Solution

The fourth proportional to 643.59, 892.26 and 621.05 is: 861.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.59 : 892.26 = 621.05 : x
  2. Step 2: Convert to fraction form
    643.59/892.26 = 621.05/x
  3. Step 3: Cross multiply
    643.59x = 892.26 × 621.05
  4. Step 4: Simplify right side
    643.59x = 554,133.61
  5. Step 5: Solve for x
    x = 554,133.61/643.59
  6. Step 6: Final answer
    x = 861.00

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.