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Finding the Fourth Proportional to 67.21, 100.39 and 66.67

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Solution

The fourth proportional to 67.21, 100.39 and 66.67 is: 99.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    67.21 : 100.39 = 66.67 : x
  2. Step 2: Convert to fraction form
    67.21/100.39 = 66.67/x
  3. Step 3: Cross multiply
    67.21x = 100.39 × 66.67
  4. Step 4: Simplify right side
    67.21x = 6,693.00
  5. Step 5: Solve for x
    x = 6,693.00/67.21
  6. Step 6: Final answer
    x = 99.58

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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.