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Finding the Fourth Proportional to 112.41, 155.12 and 65.78

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Solution

The fourth proportional to 112.41, 155.12 and 65.78 is: 90.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.41 : 155.12 = 65.78 : x
  2. Step 2: Convert to fraction form
    112.41/155.12 = 65.78/x
  3. Step 3: Cross multiply
    112.41x = 155.12 × 65.78
  4. Step 4: Simplify right side
    112.41x = 10,203.79
  5. Step 5: Solve for x
    x = 10,203.79/112.41
  6. Step 6: Final answer
    x = 90.77

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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.