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Finding the Fourth Proportional to 643.63, 887.43 and 381.55

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Solution

The fourth proportional to 643.63, 887.43 and 381.55 is: 526.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.63 : 887.43 = 381.55 : x
  2. Step 2: Convert to fraction form
    643.63/887.43 = 381.55/x
  3. Step 3: Cross multiply
    643.63x = 887.43 × 381.55
  4. Step 4: Simplify right side
    643.63x = 338,598.92
  5. Step 5: Solve for x
    x = 338,598.92/643.63
  6. Step 6: Final answer
    x = 526.08

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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.