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Finding the Fourth Proportional to 211.31, 291.31 and 145.70

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Solution

The fourth proportional to 211.31, 291.31 and 145.70 is: 200.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.31 : 291.31 = 145.70 : x
  2. Step 2: Convert to fraction form
    211.31/291.31 = 145.70/x
  3. Step 3: Cross multiply
    211.31x = 291.31 × 145.70
  4. Step 4: Simplify right side
    211.31x = 42,443.87
  5. Step 5: Solve for x
    x = 42,443.87/211.31
  6. Step 6: Final answer
    x = 200.86

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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.