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Finding the Fourth Proportional to 128.78, 177.84 and 124.22

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Solution

The fourth proportional to 128.78, 177.84 and 124.22 is: 171.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.78 : 177.84 = 124.22 : x
  2. Step 2: Convert to fraction form
    128.78/177.84 = 124.22/x
  3. Step 3: Cross multiply
    128.78x = 177.84 × 124.22
  4. Step 4: Simplify right side
    128.78x = 22,090.40
  5. Step 5: Solve for x
    x = 22,090.40/128.78
  6. Step 6: Final answer
    x = 171.54

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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.