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Finding the Fourth Proportional to 621.65, 857.63 and 385.43

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Solution

The fourth proportional to 621.65, 857.63 and 385.43 is: 531.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.65 : 857.63 = 385.43 : x
  2. Step 2: Convert to fraction form
    621.65/857.63 = 385.43/x
  3. Step 3: Cross multiply
    621.65x = 857.63 × 385.43
  4. Step 4: Simplify right side
    621.65x = 330,554.40
  5. Step 5: Solve for x
    x = 330,554.40/621.65
  6. Step 6: Final answer
    x = 531.74

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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.