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Finding the Fourth Proportional to 78.98, 108.87 and 65.14

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Solution

The fourth proportional to 78.98, 108.87 and 65.14 is: 89.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.98 : 108.87 = 65.14 : x
  2. Step 2: Convert to fraction form
    78.98/108.87 = 65.14/x
  3. Step 3: Cross multiply
    78.98x = 108.87 × 65.14
  4. Step 4: Simplify right side
    78.98x = 7,091.25
  5. Step 5: Solve for x
    x = 7,091.25/78.98
  6. Step 6: Final answer
    x = 89.79

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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.