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Finding the Fourth Proportional to 621.80, 858.02 and 385.82

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Solution

The fourth proportional to 621.80, 858.02 and 385.82 is: 532.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.80 : 858.02 = 385.82 : x
  2. Step 2: Convert to fraction form
    621.80/858.02 = 385.82/x
  3. Step 3: Cross multiply
    621.80x = 858.02 × 385.82
  4. Step 4: Simplify right side
    621.80x = 331,041.28
  5. Step 5: Solve for x
    x = 331,041.28/621.80
  6. Step 6: Final answer
    x = 532.39

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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.