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Finding the Fourth Proportional to 643.12, 887.02 and 394.23

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Solution

The fourth proportional to 643.12, 887.02 and 394.23 is: 543.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.12 : 887.02 = 394.23 : x
  2. Step 2: Convert to fraction form
    643.12/887.02 = 394.23/x
  3. Step 3: Cross multiply
    643.12x = 887.02 × 394.23
  4. Step 4: Simplify right side
    643.12x = 349,692.24
  5. Step 5: Solve for x
    x = 349,692.24/643.12
  6. Step 6: Final answer
    x = 543.74

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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.