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Finding the Fourth Proportional to 89.90, 123.94 and 57.14

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Solution

The fourth proportional to 89.90, 123.94 and 57.14 is: 78.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.90 : 123.94 = 57.14 : x
  2. Step 2: Convert to fraction form
    89.90/123.94 = 57.14/x
  3. Step 3: Cross multiply
    89.90x = 123.94 × 57.14
  4. Step 4: Simplify right side
    89.90x = 7,081.93
  5. Step 5: Solve for x
    x = 7,081.93/89.90
  6. Step 6: Final answer
    x = 78.78

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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.