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Finding the Fourth Proportional to 621.65, 857.67 and 385.76

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Solution

The fourth proportional to 621.65, 857.67 and 385.76 is: 532.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.65 : 857.67 = 385.76 : x
  2. Step 2: Convert to fraction form
    621.65/857.67 = 385.76/x
  3. Step 3: Cross multiply
    621.65x = 857.67 × 385.76
  4. Step 4: Simplify right side
    621.65x = 330,850.49
  5. Step 5: Solve for x
    x = 330,850.49/621.65
  6. Step 6: Final answer
    x = 532.22

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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.