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Finding the Fourth Proportional to 323.43, 485.34 and 128.39

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Solution

The fourth proportional to 323.43, 485.34 and 128.39 is: 192.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    323.43 : 485.34 = 128.39 : x
  2. Step 2: Convert to fraction form
    323.43/485.34 = 128.39/x
  3. Step 3: Cross multiply
    323.43x = 485.34 × 128.39
  4. Step 4: Simplify right side
    323.43x = 62,312.16
  5. Step 5: Solve for x
    x = 62,312.16/323.43
  6. Step 6: Final answer
    x = 192.66

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.