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Finding the Fourth Proportional to 135.69, 187.45 and 128.85

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Solution

The fourth proportional to 135.69, 187.45 and 128.85 is: 178.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.69 : 187.45 = 128.85 : x
  2. Step 2: Convert to fraction form
    135.69/187.45 = 128.85/x
  3. Step 3: Cross multiply
    135.69x = 187.45 × 128.85
  4. Step 4: Simplify right side
    135.69x = 24,152.93
  5. Step 5: Solve for x
    x = 24,152.93/135.69
  6. Step 6: Final answer
    x = 178.00

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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.