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Finding the Fourth Proportional to 156.78, 235.19 and 128.14

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Solution

The fourth proportional to 156.78, 235.19 and 128.14 is: 192.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    156.78 : 235.19 = 128.14 : x
  2. Step 2: Convert to fraction form
    156.78/235.19 = 128.14/x
  3. Step 3: Cross multiply
    156.78x = 235.19 × 128.14
  4. Step 4: Simplify right side
    156.78x = 30,136.98
  5. Step 5: Solve for x
    x = 30,136.98/156.78
  6. Step 6: Final answer
    x = 192.22

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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.