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Finding the Fourth Proportional to 138.32, 208.40 and 123.58

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Solution

The fourth proportional to 138.32, 208.40 and 123.58 is: 186.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.32 : 208.40 = 123.58 : x
  2. Step 2: Convert to fraction form
    138.32/208.40 = 123.58/x
  3. Step 3: Cross multiply
    138.32x = 208.40 × 123.58
  4. Step 4: Simplify right side
    138.32x = 25,754.07
  5. Step 5: Solve for x
    x = 25,754.07/138.32
  6. Step 6: Final answer
    x = 186.19

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.