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Finding the Fourth Proportional to 139.42, 208.95 and 66.25

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Solution

The fourth proportional to 139.42, 208.95 and 66.25 is: 99.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.42 : 208.95 = 66.25 : x
  2. Step 2: Convert to fraction form
    139.42/208.95 = 66.25/x
  3. Step 3: Cross multiply
    139.42x = 208.95 × 66.25
  4. Step 4: Simplify right side
    139.42x = 13,842.94
  5. Step 5: Solve for x
    x = 13,842.94/139.42
  6. Step 6: Final answer
    x = 99.29

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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.