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Finding the Fourth Proportional to 71.64, 99.09 and 69.21

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Solution

The fourth proportional to 71.64, 99.09 and 69.21 is: 95.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.64 : 99.09 = 69.21 : x
  2. Step 2: Convert to fraction form
    71.64/99.09 = 69.21/x
  3. Step 3: Cross multiply
    71.64x = 99.09 × 69.21
  4. Step 4: Simplify right side
    71.64x = 6,858.02
  5. Step 5: Solve for x
    x = 6,858.02/71.64
  6. Step 6: Final answer
    x = 95.73

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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.