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Finding the Fourth Proportional to 210.31, 315.21 and 149.31

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Solution

The fourth proportional to 210.31, 315.21 and 149.31 is: 223.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.31 : 315.21 = 149.31 : x
  2. Step 2: Convert to fraction form
    210.31/315.21 = 149.31/x
  3. Step 3: Cross multiply
    210.31x = 315.21 × 149.31
  4. Step 4: Simplify right side
    210.31x = 47,064.05
  5. Step 5: Solve for x
    x = 47,064.05/210.31
  6. Step 6: Final answer
    x = 223.78

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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.