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Finding the Fourth Proportional to 198.79, 298.09 and 90.51

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Solution

The fourth proportional to 198.79, 298.09 and 90.51 is: 135.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    198.79 : 298.09 = 90.51 : x
  2. Step 2: Convert to fraction form
    198.79/298.09 = 90.51/x
  3. Step 3: Cross multiply
    198.79x = 298.09 × 90.51
  4. Step 4: Simplify right side
    198.79x = 26,980.13
  5. Step 5: Solve for x
    x = 26,980.13/198.79
  6. Step 6: Final answer
    x = 135.72

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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.