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Finding the Fourth Proportional to 183.78, 253.89 and 128.70

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Solution

The fourth proportional to 183.78, 253.89 and 128.70 is: 177.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    183.78 : 253.89 = 128.70 : x
  2. Step 2: Convert to fraction form
    183.78/253.89 = 128.70/x
  3. Step 3: Cross multiply
    183.78x = 253.89 × 128.70
  4. Step 4: Simplify right side
    183.78x = 32,675.64
  5. Step 5: Solve for x
    x = 32,675.64/183.78
  6. Step 6: Final answer
    x = 177.80

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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.