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Finding the Fourth Proportional to 128.52, 177.28 and 84.32

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Solution

The fourth proportional to 128.52, 177.28 and 84.32 is: 116.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.52 : 177.28 = 84.32 : x
  2. Step 2: Convert to fraction form
    128.52/177.28 = 84.32/x
  3. Step 3: Cross multiply
    128.52x = 177.28 × 84.32
  4. Step 4: Simplify right side
    128.52x = 14,948.25
  5. Step 5: Solve for x
    x = 14,948.25/128.52
  6. Step 6: Final answer
    x = 116.31

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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.