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Finding the Fourth Proportional to 77.61, 107.06 and 65.39

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Solution

The fourth proportional to 77.61, 107.06 and 65.39 is: 90.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.61 : 107.06 = 65.39 : x
  2. Step 2: Convert to fraction form
    77.61/107.06 = 65.39/x
  3. Step 3: Cross multiply
    77.61x = 107.06 × 65.39
  4. Step 4: Simplify right side
    77.61x = 6,999.79
  5. Step 5: Solve for x
    x = 6,999.79/77.61
  6. Step 6: Final answer
    x = 90.19

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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.