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Finding the Fourth Proportional to 214.31, 321.53 and 90.85

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Solution

The fourth proportional to 214.31, 321.53 and 90.85 is: 136.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    214.31 : 321.53 = 90.85 : x
  2. Step 2: Convert to fraction form
    214.31/321.53 = 90.85/x
  3. Step 3: Cross multiply
    214.31x = 321.53 × 90.85
  4. Step 4: Simplify right side
    214.31x = 29,210.20
  5. Step 5: Solve for x
    x = 29,210.20/214.31
  6. Step 6: Final answer
    x = 136.30

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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.