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Finding the Fourth Proportional to 215.25, 322.91 and 128.65

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Solution

The fourth proportional to 215.25, 322.91 and 128.65 is: 193.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.25 : 322.91 = 128.65 : x
  2. Step 2: Convert to fraction form
    215.25/322.91 = 128.65/x
  3. Step 3: Cross multiply
    215.25x = 322.91 × 128.65
  4. Step 4: Simplify right side
    215.25x = 41,542.37
  5. Step 5: Solve for x
    x = 41,542.37/215.25
  6. Step 6: Final answer
    x = 193.00

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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.