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Finding the Fourth Proportional to 77.00, 106.20 and 69.21

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Solution

The fourth proportional to 77.00, 106.20 and 69.21 is: 95.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.00 : 106.20 = 69.21 : x
  2. Step 2: Convert to fraction form
    77.00/106.20 = 69.21/x
  3. Step 3: Cross multiply
    77.00x = 106.20 × 69.21
  4. Step 4: Simplify right side
    77.00x = 7,350.10
  5. Step 5: Solve for x
    x = 7,350.10/77.00
  6. Step 6: Final answer
    x = 95.46

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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.