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Finding the Fourth Proportional to 77.37, 106.70 and 65.70

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Solution

The fourth proportional to 77.37, 106.70 and 65.70 is: 90.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.37 : 106.70 = 65.70 : x
  2. Step 2: Convert to fraction form
    77.37/106.70 = 65.70/x
  3. Step 3: Cross multiply
    77.37x = 106.70 × 65.70
  4. Step 4: Simplify right side
    77.37x = 7,009.86
  5. Step 5: Solve for x
    x = 7,009.86/77.37
  6. Step 6: Final answer
    x = 90.61

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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.