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Finding the Fourth Proportional to 621.55, 858.05 and 488.49

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Solution

The fourth proportional to 621.55, 858.05 and 488.49 is: 674.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.55 : 858.05 = 488.49 : x
  2. Step 2: Convert to fraction form
    621.55/858.05 = 488.49/x
  3. Step 3: Cross multiply
    621.55x = 858.05 × 488.49
  4. Step 4: Simplify right side
    621.55x = 419,148.84
  5. Step 5: Solve for x
    x = 419,148.84/621.55
  6. Step 6: Final answer
    x = 674.36

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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.