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Finding the Fourth Proportional to 159.31, 219.85 and 90.31

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Solution

The fourth proportional to 159.31, 219.85 and 90.31 is: 124.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    159.31 : 219.85 = 90.31 : x
  2. Step 2: Convert to fraction form
    159.31/219.85 = 90.31/x
  3. Step 3: Cross multiply
    159.31x = 219.85 × 90.31
  4. Step 4: Simplify right side
    159.31x = 19,855.32
  5. Step 5: Solve for x
    x = 19,855.32/159.31
  6. Step 6: Final answer
    x = 124.63

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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.