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Finding the Fourth Proportional to 77.40, 107.37 and 72.90

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Solution

The fourth proportional to 77.40, 107.37 and 72.90 is: 101.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.40 : 107.37 = 72.90 : x
  2. Step 2: Convert to fraction form
    77.40/107.37 = 72.90/x
  3. Step 3: Cross multiply
    77.40x = 107.37 × 72.90
  4. Step 4: Simplify right side
    77.40x = 7,827.27
  5. Step 5: Solve for x
    x = 7,827.27/77.40
  6. Step 6: Final answer
    x = 101.13

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.