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Finding the Fourth Proportional to 323.78, 485.58 and 128.69

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Solution

The fourth proportional to 323.78, 485.58 and 128.69 is: 193.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    323.78 : 485.58 = 128.69 : x
  2. Step 2: Convert to fraction form
    323.78/485.58 = 128.69/x
  3. Step 3: Cross multiply
    323.78x = 485.58 × 128.69
  4. Step 4: Simplify right side
    323.78x = 62,490.50
  5. Step 5: Solve for x
    x = 62,490.50/323.78
  6. Step 6: Final answer
    x = 193.00

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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.