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Finding the Fourth Proportional to 84.21, 116.32 and 67.90

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Solution

The fourth proportional to 84.21, 116.32 and 67.90 is: 93.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.21 : 116.32 = 67.90 : x
  2. Step 2: Convert to fraction form
    84.21/116.32 = 67.90/x
  3. Step 3: Cross multiply
    84.21x = 116.32 × 67.90
  4. Step 4: Simplify right side
    84.21x = 7,897.55
  5. Step 5: Solve for x
    x = 7,897.55/84.21
  6. Step 6: Final answer
    x = 93.78

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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.