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Finding the Fourth Proportional to 78.06, 108.47 and 77.22

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Solution

The fourth proportional to 78.06, 108.47 and 77.22 is: 107.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.06 : 108.47 = 77.22 : x
  2. Step 2: Convert to fraction form
    78.06/108.47 = 77.22/x
  3. Step 3: Cross multiply
    78.06x = 108.47 × 77.22
  4. Step 4: Simplify right side
    78.06x = 8,376.25
  5. Step 5: Solve for x
    x = 8,376.25/78.06
  6. Step 6: Final answer
    x = 107.30

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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.