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Finding the Fourth Proportional to 211.05, 291.15 and 123.71

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Solution

The fourth proportional to 211.05, 291.15 and 123.71 is: 170.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.05 : 291.15 = 123.71 : x
  2. Step 2: Convert to fraction form
    211.05/291.15 = 123.71/x
  3. Step 3: Cross multiply
    211.05x = 291.15 × 123.71
  4. Step 4: Simplify right side
    211.05x = 36,016.71
  5. Step 5: Solve for x
    x = 36,016.71/211.05
  6. Step 6: Final answer
    x = 170.65

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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.