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Finding the Fourth Proportional to 647.94, 971.90 and 215.09

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Solution

The fourth proportional to 647.94, 971.90 and 215.09 is: 322.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.94 : 971.90 = 215.09 : x
  2. Step 2: Convert to fraction form
    647.94/971.90 = 215.09/x
  3. Step 3: Cross multiply
    647.94x = 971.90 × 215.09
  4. Step 4: Simplify right side
    647.94x = 209,045.97
  5. Step 5: Solve for x
    x = 209,045.97/647.94
  6. Step 6: Final answer
    x = 322.63

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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.