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Finding the Fourth Proportional to 105.78, 157.92 and 99.66

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Solution

The fourth proportional to 105.78, 157.92 and 99.66 is: 148.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.78 : 157.92 = 99.66 : x
  2. Step 2: Convert to fraction form
    105.78/157.92 = 99.66/x
  3. Step 3: Cross multiply
    105.78x = 157.92 × 99.66
  4. Step 4: Simplify right side
    105.78x = 15,738.31
  5. Step 5: Solve for x
    x = 15,738.31/105.78
  6. Step 6: Final answer
    x = 148.78

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.