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Finding the Fourth Proportional to 153.30, 211.07 and 128.69

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Solution

The fourth proportional to 153.30, 211.07 and 128.69 is: 177.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    153.30 : 211.07 = 128.69 : x
  2. Step 2: Convert to fraction form
    153.30/211.07 = 128.69/x
  3. Step 3: Cross multiply
    153.30x = 211.07 × 128.69
  4. Step 4: Simplify right side
    153.30x = 27,160.90
  5. Step 5: Solve for x
    x = 27,160.90/153.30
  6. Step 6: Final answer
    x = 177.17

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.