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Finding the Fourth Proportional to 215.67, 322.95 and 128.91

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Solution

The fourth proportional to 215.67, 322.95 and 128.91 is: 193.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.67 : 322.95 = 128.91 : x
  2. Step 2: Convert to fraction form
    215.67/322.95 = 128.91/x
  3. Step 3: Cross multiply
    215.67x = 322.95 × 128.91
  4. Step 4: Simplify right side
    215.67x = 41,631.48
  5. Step 5: Solve for x
    x = 41,631.48/215.67
  6. Step 6: Final answer
    x = 193.03

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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.