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Finding the Fourth Proportional to 149.19, 205.90 and 99.31

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Solution

The fourth proportional to 149.19, 205.90 and 99.31 is: 137.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    149.19 : 205.90 = 99.31 : x
  2. Step 2: Convert to fraction form
    149.19/205.90 = 99.31/x
  3. Step 3: Cross multiply
    149.19x = 205.90 × 99.31
  4. Step 4: Simplify right side
    149.19x = 20,447.93
  5. Step 5: Solve for x
    x = 20,447.93/149.19
  6. Step 6: Final answer
    x = 137.06

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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.