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Finding the Fourth Proportional to 177.80, 245.15 and 128.66

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Solution

The fourth proportional to 177.80, 245.15 and 128.66 is: 177.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    177.80 : 245.15 = 128.66 : x
  2. Step 2: Convert to fraction form
    177.80/245.15 = 128.66/x
  3. Step 3: Cross multiply
    177.80x = 245.15 × 128.66
  4. Step 4: Simplify right side
    177.80x = 31,540.97
  5. Step 5: Solve for x
    x = 31,540.97/177.80
  6. Step 6: Final answer
    x = 177.39

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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.