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Finding the Fourth Proportional to 153.05, 211.19 and 86.65

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Solution

The fourth proportional to 153.05, 211.19 and 86.65 is: 119.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    153.05 : 211.19 = 86.65 : x
  2. Step 2: Convert to fraction form
    153.05/211.19 = 86.65/x
  3. Step 3: Cross multiply
    153.05x = 211.19 × 86.65
  4. Step 4: Simplify right side
    153.05x = 18,298.65
  5. Step 5: Solve for x
    x = 18,298.65/153.05
  6. Step 6: Final answer
    x = 119.56

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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.