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Finding the Fourth Proportional to 88.20, 121.95 and 84.38

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Solution

The fourth proportional to 88.20, 121.95 and 84.38 is: 116.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.20 : 121.95 = 84.38 : x
  2. Step 2: Convert to fraction form
    88.20/121.95 = 84.38/x
  3. Step 3: Cross multiply
    88.20x = 121.95 × 84.38
  4. Step 4: Simplify right side
    88.20x = 10,290.14
  5. Step 5: Solve for x
    x = 10,290.14/88.20
  6. Step 6: Final answer
    x = 116.67

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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.