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Finding the Fourth Proportional to 643.31, 887.57 and 394.51

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Solution

The fourth proportional to 643.31, 887.57 and 394.51 is: 544.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.31 : 887.57 = 394.51 : x
  2. Step 2: Convert to fraction form
    643.31/887.57 = 394.51/x
  3. Step 3: Cross multiply
    643.31x = 887.57 × 394.51
  4. Step 4: Simplify right side
    643.31x = 350,151.05
  5. Step 5: Solve for x
    x = 350,151.05/643.31
  6. Step 6: Final answer
    x = 544.29

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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.