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Finding the Fourth Proportional to 170.38, 235.15 and 128.87

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Solution

The fourth proportional to 170.38, 235.15 and 128.87 is: 177.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    170.38 : 235.15 = 128.87 : x
  2. Step 2: Convert to fraction form
    170.38/235.15 = 128.87/x
  3. Step 3: Cross multiply
    170.38x = 235.15 × 128.87
  4. Step 4: Simplify right side
    170.38x = 30,303.78
  5. Step 5: Solve for x
    x = 30,303.78/170.38
  6. Step 6: Final answer
    x = 177.86

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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.