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Finding the Fourth Proportional to 100.04, 137.90 and 79.28

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Solution

The fourth proportional to 100.04, 137.90 and 79.28 is: 109.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.04 : 137.90 = 79.28 : x
  2. Step 2: Convert to fraction form
    100.04/137.90 = 79.28/x
  3. Step 3: Cross multiply
    100.04x = 137.90 × 79.28
  4. Step 4: Simplify right side
    100.04x = 10,932.74
  5. Step 5: Solve for x
    x = 10,932.74/100.04
  6. Step 6: Final answer
    x = 109.29

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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.