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Finding the Fourth Proportional to 96.78, 133.40 and 89.90

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Solution

The fourth proportional to 96.78, 133.40 and 89.90 is: 123.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    96.78 : 133.40 = 89.90 : x
  2. Step 2: Convert to fraction form
    96.78/133.40 = 89.90/x
  3. Step 3: Cross multiply
    96.78x = 133.40 × 89.90
  4. Step 4: Simplify right side
    96.78x = 11,991.54
  5. Step 5: Solve for x
    x = 11,991.54/96.78
  6. Step 6: Final answer
    x = 123.91

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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.