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Finding the Fourth Proportional to 187.28, 258.28 and 138.28

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Solution

The fourth proportional to 187.28, 258.28 and 138.28 is: 190.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    187.28 : 258.28 = 138.28 : x
  2. Step 2: Convert to fraction form
    187.28/258.28 = 138.28/x
  3. Step 3: Cross multiply
    187.28x = 258.28 × 138.28
  4. Step 4: Simplify right side
    187.28x = 35,714.96
  5. Step 5: Solve for x
    x = 35,714.96/187.28
  6. Step 6: Final answer
    x = 190.70

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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.