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Finding the Fourth Proportional to 151.24, 208.70 and 85.72

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Solution

The fourth proportional to 151.24, 208.70 and 85.72 is: 118.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    151.24 : 208.70 = 85.72 : x
  2. Step 2: Convert to fraction form
    151.24/208.70 = 85.72/x
  3. Step 3: Cross multiply
    151.24x = 208.70 × 85.72
  4. Step 4: Simplify right side
    151.24x = 17,889.76
  5. Step 5: Solve for x
    x = 17,889.76/151.24
  6. Step 6: Final answer
    x = 118.29

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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.