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Finding the Fourth Proportional to 151.40, 208.80 and 137.72

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Solution

The fourth proportional to 151.40, 208.80 and 137.72 is: 189.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    151.40 : 208.80 = 137.72 : x
  2. Step 2: Convert to fraction form
    151.40/208.80 = 137.72/x
  3. Step 3: Cross multiply
    151.40x = 208.80 × 137.72
  4. Step 4: Simplify right side
    151.40x = 28,755.94
  5. Step 5: Solve for x
    x = 28,755.94/151.40
  6. Step 6: Final answer
    x = 189.93

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.