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Finding the Fourth Proportional to 106.80, 147.72 and 103.20

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Solution

The fourth proportional to 106.80, 147.72 and 103.20 is: 142.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    106.80 : 147.72 = 103.20 : x
  2. Step 2: Convert to fraction form
    106.80/147.72 = 103.20/x
  3. Step 3: Cross multiply
    106.80x = 147.72 × 103.20
  4. Step 4: Simplify right side
    106.80x = 15,244.70
  5. Step 5: Solve for x
    x = 15,244.70/106.80
  6. Step 6: Final answer
    x = 142.74

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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.