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Finding the Fourth Proportional to 72.20, 99.07 and 69.64

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Solution

The fourth proportional to 72.20, 99.07 and 69.64 is: 95.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.20 : 99.07 = 69.64 : x
  2. Step 2: Convert to fraction form
    72.20/99.07 = 69.64/x
  3. Step 3: Cross multiply
    72.20x = 99.07 × 69.64
  4. Step 4: Simplify right side
    72.20x = 6,899.23
  5. Step 5: Solve for x
    x = 6,899.23/72.20
  6. Step 6: Final answer
    x = 95.56

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.