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Finding the Fourth Proportional to 213.95, 320.90 and 126.15

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Solution

The fourth proportional to 213.95, 320.90 and 126.15 is: 189.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    213.95 : 320.90 = 126.15 : x
  2. Step 2: Convert to fraction form
    213.95/320.90 = 126.15/x
  3. Step 3: Cross multiply
    213.95x = 320.90 × 126.15
  4. Step 4: Simplify right side
    213.95x = 40,480.90
  5. Step 5: Solve for x
    x = 40,480.90/213.95
  6. Step 6: Final answer
    x = 189.21

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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.