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Finding the Fourth Proportional to 388.96, 583.46 and 128.98

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Solution

The fourth proportional to 388.96, 583.46 and 128.98 is: 193.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.96 : 583.46 = 128.98 : x
  2. Step 2: Convert to fraction form
    388.96/583.46 = 128.98/x
  3. Step 3: Cross multiply
    388.96x = 583.46 × 128.98
  4. Step 4: Simplify right side
    388.96x = 75,254.76
  5. Step 5: Solve for x
    x = 75,254.76/388.96
  6. Step 6: Final answer
    x = 193.48

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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.