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Finding the Fourth Proportional to 127.55, 190.88 and 78.78

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Solution

The fourth proportional to 127.55, 190.88 and 78.78 is: 117.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    127.55 : 190.88 = 78.78 : x
  2. Step 2: Convert to fraction form
    127.55/190.88 = 78.78/x
  3. Step 3: Cross multiply
    127.55x = 190.88 × 78.78
  4. Step 4: Simplify right side
    127.55x = 15,036.18
  5. Step 5: Solve for x
    x = 15,036.18/127.55
  6. Step 6: Final answer
    x = 117.89

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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.