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Finding the Fourth Proportional to 187.26, 258.51 and 128.56

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Solution

The fourth proportional to 187.26, 258.51 and 128.56 is: 177.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    187.26 : 258.51 = 128.56 : x
  2. Step 2: Convert to fraction form
    187.26/258.51 = 128.56/x
  3. Step 3: Cross multiply
    187.26x = 258.51 × 128.56
  4. Step 4: Simplify right side
    187.26x = 33,232.75
  5. Step 5: Solve for x
    x = 33,232.75/187.26
  6. Step 6: Final answer
    x = 177.47

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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.