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Finding the Fourth Proportional to 80.69, 121.51 and 70.67

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Solution

The fourth proportional to 80.69, 121.51 and 70.67 is: 106.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.69 : 121.51 = 70.67 : x
  2. Step 2: Convert to fraction form
    80.69/121.51 = 70.67/x
  3. Step 3: Cross multiply
    80.69x = 121.51 × 70.67
  4. Step 4: Simplify right side
    80.69x = 8,587.11
  5. Step 5: Solve for x
    x = 8,587.11/80.69
  6. Step 6: Final answer
    x = 106.42

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.