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Finding the Fourth Proportional to 388.63, 582.81 and 128.58

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Solution

The fourth proportional to 388.63, 582.81 and 128.58 is: 192.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.63 : 582.81 = 128.58 : x
  2. Step 2: Convert to fraction form
    388.63/582.81 = 128.58/x
  3. Step 3: Cross multiply
    388.63x = 582.81 × 128.58
  4. Step 4: Simplify right side
    388.63x = 74,938.52
  5. Step 5: Solve for x
    x = 74,938.52/388.63
  6. Step 6: Final answer
    x = 192.83

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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.