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Finding the Fourth Proportional to 77, 115.63 and 71.39

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Solution

The fourth proportional to 77, 115.63 and 71.39 is: 107.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    77 : 115.63 = 71.39 : x
  2. Step 2: Convert to fraction form
    77/115.63 = 71.39/x
  3. Step 3: Cross multiply
    77x = 115.63 × 71.39
  4. Step 4: Simplify right side
    77x = 8,254.83
  5. Step 5: Solve for x
    x = 8,254.83/77
  6. Step 6: Final answer
    x = 107.21

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.