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Finding the Fourth Proportional to 388.06, 582.19 and 128.12

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Solution

The fourth proportional to 388.06, 582.19 and 128.12 is: 192.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.06 : 582.19 = 128.12 : x
  2. Step 2: Convert to fraction form
    388.06/582.19 = 128.12/x
  3. Step 3: Cross multiply
    388.06x = 582.19 × 128.12
  4. Step 4: Simplify right side
    388.06x = 74,586.95
  5. Step 5: Solve for x
    x = 74,586.95/388.06
  6. Step 6: Final answer
    x = 192.21

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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.