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Finding the Fourth Proportional to 643.90, 887.61 and 395.03

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Solution

The fourth proportional to 643.90, 887.61 and 395.03 is: 544.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.90 : 887.61 = 395.03 : x
  2. Step 2: Convert to fraction form
    643.90/887.61 = 395.03/x
  3. Step 3: Cross multiply
    643.90x = 887.61 × 395.03
  4. Step 4: Simplify right side
    643.90x = 350,629.06
  5. Step 5: Solve for x
    x = 350,629.06/643.90
  6. Step 6: Final answer
    x = 544.54

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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.