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Finding the Fourth Proportional to 139.64, 209.12 and 70.99

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Solution

The fourth proportional to 139.64, 209.12 and 70.99 is: 106.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.64 : 209.12 = 70.99 : x
  2. Step 2: Convert to fraction form
    139.64/209.12 = 70.99/x
  3. Step 3: Cross multiply
    139.64x = 209.12 × 70.99
  4. Step 4: Simplify right side
    139.64x = 14,844.38
  5. Step 5: Solve for x
    x = 14,844.38/139.64
  6. Step 6: Final answer
    x = 106.31

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Why These Related Problems?

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