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Finding the Fourth Proportional to 139.95, 209.75 and 71.43

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Solution

The fourth proportional to 139.95, 209.75 and 71.43 is: 107.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.95 : 209.75 = 71.43 : x
  2. Step 2: Convert to fraction form
    139.95/209.75 = 71.43/x
  3. Step 3: Cross multiply
    139.95x = 209.75 × 71.43
  4. Step 4: Simplify right side
    139.95x = 14,982.09
  5. Step 5: Solve for x
    x = 14,982.09/139.95
  6. Step 6: Final answer
    x = 107.05

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These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.