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Finding the Fourth Proportional to 111.68, 154.13 and 65.05

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Solution

The fourth proportional to 111.68, 154.13 and 65.05 is: 89.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    111.68 : 154.13 = 65.05 : x
  2. Step 2: Convert to fraction form
    111.68/154.13 = 65.05/x
  3. Step 3: Cross multiply
    111.68x = 154.13 × 65.05
  4. Step 4: Simplify right side
    111.68x = 10,025.93
  5. Step 5: Solve for x
    x = 10,025.93/111.68
  6. Step 6: Final answer
    x = 89.78

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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.