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Finding the Fourth Proportional to 231.64, 319.62 and 138.40

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Solution

The fourth proportional to 231.64, 319.62 and 138.40 is: 190.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    231.64 : 319.62 = 138.40 : x
  2. Step 2: Convert to fraction form
    231.64/319.62 = 138.40/x
  3. Step 3: Cross multiply
    231.64x = 319.62 × 138.40
  4. Step 4: Simplify right side
    231.64x = 44,235.41
  5. Step 5: Solve for x
    x = 44,235.41/231.64
  6. Step 6: Final answer
    x = 190.97

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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.