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Finding the Fourth Proportional to 128.60, 177.54 and 89.32

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Solution

The fourth proportional to 128.60, 177.54 and 89.32 is: 123.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.60 : 177.54 = 89.32 : x
  2. Step 2: Convert to fraction form
    128.60/177.54 = 89.32/x
  3. Step 3: Cross multiply
    128.60x = 177.54 × 89.32
  4. Step 4: Simplify right side
    128.60x = 15,857.87
  5. Step 5: Solve for x
    x = 15,857.87/128.60
  6. Step 6: Final answer
    x = 123.31

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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.