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Finding the Fourth Proportional to 211.21, 291.49 and 123.88

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Solution

The fourth proportional to 211.21, 291.49 and 123.88 is: 170.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.21 : 291.49 = 123.88 : x
  2. Step 2: Convert to fraction form
    211.21/291.49 = 123.88/x
  3. Step 3: Cross multiply
    211.21x = 291.49 × 123.88
  4. Step 4: Simplify right side
    211.21x = 36,108.01
  5. Step 5: Solve for x
    x = 36,108.01/211.21
  6. Step 6: Final answer
    x = 170.96

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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.