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Finding the Fourth Proportional to 149.02, 205.46 and 90.78

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Solution

The fourth proportional to 149.02, 205.46 and 90.78 is: 125.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    149.02 : 205.46 = 90.78 : x
  2. Step 2: Convert to fraction form
    149.02/205.46 = 90.78/x
  3. Step 3: Cross multiply
    149.02x = 205.46 × 90.78
  4. Step 4: Simplify right side
    149.02x = 18,651.66
  5. Step 5: Solve for x
    x = 18,651.66/149.02
  6. Step 6: Final answer
    x = 125.16

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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.