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Finding the Fourth Proportional to 647.91, 971.58 and 209.09

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Solution

The fourth proportional to 647.91, 971.58 and 209.09 is: 313.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.91 : 971.58 = 209.09 : x
  2. Step 2: Convert to fraction form
    647.91/971.58 = 209.09/x
  3. Step 3: Cross multiply
    647.91x = 971.58 × 209.09
  4. Step 4: Simplify right side
    647.91x = 203,142.80
  5. Step 5: Solve for x
    x = 203,142.80/647.91
  6. Step 6: Final answer
    x = 313.54

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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.