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Finding the Fourth Proportional to 648.21, 972.11 and 215.25

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Solution

The fourth proportional to 648.21, 972.11 and 215.25 is: 322.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.21 : 972.11 = 215.25 : x
  2. Step 2: Convert to fraction form
    648.21/972.11 = 215.25/x
  3. Step 3: Cross multiply
    648.21x = 972.11 × 215.25
  4. Step 4: Simplify right side
    648.21x = 209,245.60
  5. Step 5: Solve for x
    x = 209,245.60/648.21
  6. Step 6: Final answer
    x = 322.81

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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.