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Finding the Fourth Proportional to 139.90, 210.21 and 113.95

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Solution

The fourth proportional to 139.90, 210.21 and 113.95 is: 171.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.90 : 210.21 = 113.95 : x
  2. Step 2: Convert to fraction form
    139.90/210.21 = 113.95/x
  3. Step 3: Cross multiply
    139.90x = 210.21 × 113.95
  4. Step 4: Simplify right side
    139.90x = 23,953.43
  5. Step 5: Solve for x
    x = 23,953.43/139.90
  6. Step 6: Final answer
    x = 171.22

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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.