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Finding the Fourth Proportional to 128.42, 191.36 and 127.35

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Solution

The fourth proportional to 128.42, 191.36 and 127.35 is: 189.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.42 : 191.36 = 127.35 : x
  2. Step 2: Convert to fraction form
    128.42/191.36 = 127.35/x
  3. Step 3: Cross multiply
    128.42x = 191.36 × 127.35
  4. Step 4: Simplify right side
    128.42x = 24,369.70
  5. Step 5: Solve for x
    x = 24,369.70/128.42
  6. Step 6: Final answer
    x = 189.77

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.