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Finding the Fourth Proportional to 99.89, 149.78 and 45.05

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Solution

The fourth proportional to 99.89, 149.78 and 45.05 is: 67.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.89 : 149.78 = 45.05 : x
  2. Step 2: Convert to fraction form
    99.89/149.78 = 45.05/x
  3. Step 3: Cross multiply
    99.89x = 149.78 × 45.05
  4. Step 4: Simplify right side
    99.89x = 6,747.36
  5. Step 5: Solve for x
    x = 6,747.36/99.89
  6. Step 6: Final answer
    x = 67.55

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.