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Finding the Fourth Proportional to 209.30, 288.87 and 139.23

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Solution

The fourth proportional to 209.30, 288.87 and 139.23 is: 192.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.30 : 288.87 = 139.23 : x
  2. Step 2: Convert to fraction form
    209.30/288.87 = 139.23/x
  3. Step 3: Cross multiply
    209.30x = 288.87 × 139.23
  4. Step 4: Simplify right side
    209.30x = 40,218.85
  5. Step 5: Solve for x
    x = 40,218.85/209.30
  6. Step 6: Final answer
    x = 192.16

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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.