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Finding the Fourth Proportional to 127.40, 191.19 and 85.63

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Solution

The fourth proportional to 127.40, 191.19 and 85.63 is: 128.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    127.40 : 191.19 = 85.63 : x
  2. Step 2: Convert to fraction form
    127.40/191.19 = 85.63/x
  3. Step 3: Cross multiply
    127.40x = 191.19 × 85.63
  4. Step 4: Simplify right side
    127.40x = 16,371.62
  5. Step 5: Solve for x
    x = 16,371.62/127.40
  6. Step 6: Final answer
    x = 128.51

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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.