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Finding the Fourth Proportional to 643.95, 888.66 and 378.57

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Solution

The fourth proportional to 643.95, 888.66 and 378.57 is: 522.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.95 : 888.66 = 378.57 : x
  2. Step 2: Convert to fraction form
    643.95/888.66 = 378.57/x
  3. Step 3: Cross multiply
    643.95x = 888.66 × 378.57
  4. Step 4: Simplify right side
    643.95x = 336,420.02
  5. Step 5: Solve for x
    x = 336,420.02/643.95
  6. Step 6: Final answer
    x = 522.43

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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.