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Finding the Fourth Proportional to 215.06, 322.09 and 128.45

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Solution

The fourth proportional to 215.06, 322.09 and 128.45 is: 192.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.06 : 322.09 = 128.45 : x
  2. Step 2: Convert to fraction form
    215.06/322.09 = 128.45/x
  3. Step 3: Cross multiply
    215.06x = 322.09 × 128.45
  4. Step 4: Simplify right side
    215.06x = 41,372.46
  5. Step 5: Solve for x
    x = 41,372.46/215.06
  6. Step 6: Final answer
    x = 192.38

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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.