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Finding the Fourth Proportional to 209.45, 288.87 and 135.74

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Solution

The fourth proportional to 209.45, 288.87 and 135.74 is: 187.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.45 : 288.87 = 135.74 : x
  2. Step 2: Convert to fraction form
    209.45/288.87 = 135.74/x
  3. Step 3: Cross multiply
    209.45x = 288.87 × 135.74
  4. Step 4: Simplify right side
    209.45x = 39,211.43
  5. Step 5: Solve for x
    x = 39,211.43/209.45
  6. Step 6: Final answer
    x = 187.21

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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.