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Finding the Fourth Proportional to 643.05, 887.78 and 422.38

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Solution

The fourth proportional to 643.05, 887.78 and 422.38 is: 583.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.05 : 887.78 = 422.38 : x
  2. Step 2: Convert to fraction form
    643.05/887.78 = 422.38/x
  3. Step 3: Cross multiply
    643.05x = 887.78 × 422.38
  4. Step 4: Simplify right side
    643.05x = 374,981.57
  5. Step 5: Solve for x
    x = 374,981.57/643.05
  6. Step 6: Final answer
    x = 583.13

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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.