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Finding the Fourth Proportional to 187.09, 257.88 and 128.77

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Solution

The fourth proportional to 187.09, 257.88 and 128.77 is: 177.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    187.09 : 257.88 = 128.77 : x
  2. Step 2: Convert to fraction form
    187.09/257.88 = 128.77/x
  3. Step 3: Cross multiply
    187.09x = 257.88 × 128.77
  4. Step 4: Simplify right side
    187.09x = 33,207.21
  5. Step 5: Solve for x
    x = 33,207.21/187.09
  6. Step 6: Final answer
    x = 177.49

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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.