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Finding the Fourth Proportional to 128.42, 192.70 and 63.42

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Solution

The fourth proportional to 128.42, 192.70 and 63.42 is: 95.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.42 : 192.70 = 63.42 : x
  2. Step 2: Convert to fraction form
    128.42/192.70 = 63.42/x
  3. Step 3: Cross multiply
    128.42x = 192.70 × 63.42
  4. Step 4: Simplify right side
    128.42x = 12,221.47
  5. Step 5: Solve for x
    x = 12,221.47/128.42
  6. Step 6: Final answer
    x = 95.16

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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.