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Finding the Fourth Proportional to 72.64, 109.60 and 69.40

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Solution

The fourth proportional to 72.64, 109.60 and 69.40 is: 104.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.64 : 109.60 = 69.40 : x
  2. Step 2: Convert to fraction form
    72.64/109.60 = 69.40/x
  3. Step 3: Cross multiply
    72.64x = 109.60 × 69.40
  4. Step 4: Simplify right side
    72.64x = 7,606.24
  5. Step 5: Solve for x
    x = 7,606.24/72.64
  6. Step 6: Final answer
    x = 104.71

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.