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Finding the Fourth Proportional to 139.68, 210.62 and 123.84

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Solution

The fourth proportional to 139.68, 210.62 and 123.84 is: 186.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.68 : 210.62 = 123.84 : x
  2. Step 2: Convert to fraction form
    139.68/210.62 = 123.84/x
  3. Step 3: Cross multiply
    139.68x = 210.62 × 123.84
  4. Step 4: Simplify right side
    139.68x = 26,083.18
  5. Step 5: Solve for x
    x = 26,083.18/139.68
  6. Step 6: Final answer
    x = 186.74

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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.