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Finding the Fourth Proportional to 128.71, 177.72 and 113.35

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Solution

The fourth proportional to 128.71, 177.72 and 113.35 is: 156.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.71 : 177.72 = 113.35 : x
  2. Step 2: Convert to fraction form
    128.71/177.72 = 113.35/x
  3. Step 3: Cross multiply
    128.71x = 177.72 × 113.35
  4. Step 4: Simplify right side
    128.71x = 20,144.56
  5. Step 5: Solve for x
    x = 20,144.56/128.71
  6. Step 6: Final answer
    x = 156.51

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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.