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Finding the Fourth Proportional to 77.30, 106.67 and 42.80

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Solution

The fourth proportional to 77.30, 106.67 and 42.80 is: 59.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.30 : 106.67 = 42.80 : x
  2. Step 2: Convert to fraction form
    77.30/106.67 = 42.80/x
  3. Step 3: Cross multiply
    77.30x = 106.67 × 42.80
  4. Step 4: Simplify right side
    77.30x = 4,564.94
  5. Step 5: Solve for x
    x = 4,564.94/77.30
  6. Step 6: Final answer
    x = 59.06

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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.