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Finding the Fourth Proportional to 128.21, 176.45 and 119.30

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Solution

The fourth proportional to 128.21, 176.45 and 119.30 is: 164.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.21 : 176.45 = 119.30 : x
  2. Step 2: Convert to fraction form
    128.21/176.45 = 119.30/x
  3. Step 3: Cross multiply
    128.21x = 176.45 × 119.30
  4. Step 4: Simplify right side
    128.21x = 21,049.01
  5. Step 5: Solve for x
    x = 21,049.01/128.21
  6. Step 6: Final answer
    x = 164.18

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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.