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Finding the Fourth Proportional to 100.75, 138.94 and 76.14

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Solution

The fourth proportional to 100.75, 138.94 and 76.14 is: 105.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.75 : 138.94 = 76.14 : x
  2. Step 2: Convert to fraction form
    100.75/138.94 = 76.14/x
  3. Step 3: Cross multiply
    100.75x = 138.94 × 76.14
  4. Step 4: Simplify right side
    100.75x = 10,578.89
  5. Step 5: Solve for x
    x = 10,578.89/100.75
  6. Step 6: Final answer
    x = 105.00

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.