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Finding the Fourth Proportional to 647.98, 971.79 and 215.17

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Solution

The fourth proportional to 647.98, 971.79 and 215.17 is: 322.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.98 : 971.79 = 215.17 : x
  2. Step 2: Convert to fraction form
    647.98/971.79 = 215.17/x
  3. Step 3: Cross multiply
    647.98x = 971.79 × 215.17
  4. Step 4: Simplify right side
    647.98x = 209,100.05
  5. Step 5: Solve for x
    x = 209,100.05/647.98
  6. Step 6: Final answer
    x = 322.70

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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.