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Finding the Fourth Proportional to 117.20, 161.40 and 84.40

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Solution

The fourth proportional to 117.20, 161.40 and 84.40 is: 116.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    117.20 : 161.40 = 84.40 : x
  2. Step 2: Convert to fraction form
    117.20/161.40 = 84.40/x
  3. Step 3: Cross multiply
    117.20x = 161.40 × 84.40
  4. Step 4: Simplify right side
    117.20x = 13,622.16
  5. Step 5: Solve for x
    x = 13,622.16/117.20
  6. Step 6: Final answer
    x = 116.23

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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.