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Finding the Fourth Proportional to 621.81, 857.20 and 434.72

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Solution

The fourth proportional to 621.81, 857.20 and 434.72 is: 599.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.81 : 857.20 = 434.72 : x
  2. Step 2: Convert to fraction form
    621.81/857.20 = 434.72/x
  3. Step 3: Cross multiply
    621.81x = 857.20 × 434.72
  4. Step 4: Simplify right side
    621.81x = 372,645.38
  5. Step 5: Solve for x
    x = 372,645.38/621.81
  6. Step 6: Final answer
    x = 599.29

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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.