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Finding the Fourth Proportional to 80.80, 121.15 and 56.47

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Solution

The fourth proportional to 80.80, 121.15 and 56.47 is: 84.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.80 : 121.15 = 56.47 : x
  2. Step 2: Convert to fraction form
    80.80/121.15 = 56.47/x
  3. Step 3: Cross multiply
    80.80x = 121.15 × 56.47
  4. Step 4: Simplify right side
    80.80x = 6,841.34
  5. Step 5: Solve for x
    x = 6,841.34/80.80
  6. Step 6: Final answer
    x = 84.67

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.