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Finding the Fourth Proportional to 427.50, 642.48 and 211.22

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Solution

The fourth proportional to 427.50, 642.48 and 211.22 is: 317.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.50 : 642.48 = 211.22 : x
  2. Step 2: Convert to fraction form
    427.50/642.48 = 211.22/x
  3. Step 3: Cross multiply
    427.50x = 642.48 × 211.22
  4. Step 4: Simplify right side
    427.50x = 135,704.63
  5. Step 5: Solve for x
    x = 135,704.63/427.50
  6. Step 6: Final answer
    x = 317.44

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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.