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Finding the Fourth Proportional to 214.20, 321.05 and 98.70

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Solution

The fourth proportional to 214.20, 321.05 and 98.70 is: 147.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    214.20 : 321.05 = 98.70 : x
  2. Step 2: Convert to fraction form
    214.20/321.05 = 98.70/x
  3. Step 3: Cross multiply
    214.20x = 321.05 × 98.70
  4. Step 4: Simplify right side
    214.20x = 31,687.14
  5. Step 5: Solve for x
    x = 31,687.14/214.20
  6. Step 6: Final answer
    x = 147.93

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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.