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Finding the Fourth Proportional to 80.64, 120.36 and 70.38

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Solution

The fourth proportional to 80.64, 120.36 and 70.38 is: 105.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.64 : 120.36 = 70.38 : x
  2. Step 2: Convert to fraction form
    80.64/120.36 = 70.38/x
  3. Step 3: Cross multiply
    80.64x = 120.36 × 70.38
  4. Step 4: Simplify right side
    80.64x = 8,470.94
  5. Step 5: Solve for x
    x = 8,470.94/80.64
  6. Step 6: Final answer
    x = 105.05

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.