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Finding the Fourth Proportional to 77.78, 107.08 and 65.48

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Solution

The fourth proportional to 77.78, 107.08 and 65.48 is: 90.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.78 : 107.08 = 65.48 : x
  2. Step 2: Convert to fraction form
    77.78/107.08 = 65.48/x
  3. Step 3: Cross multiply
    77.78x = 107.08 × 65.48
  4. Step 4: Simplify right side
    77.78x = 7,010.90
  5. Step 5: Solve for x
    x = 7,010.90/77.78
  6. Step 6: Final answer
    x = 90.13

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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.