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Finding the Fourth Proportional to 72.75, 109.72 and 71.74

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Solution

The fourth proportional to 72.75, 109.72 and 71.74 is: 108.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.75 : 109.72 = 71.74 : x
  2. Step 2: Convert to fraction form
    72.75/109.72 = 71.74/x
  3. Step 3: Cross multiply
    72.75x = 109.72 × 71.74
  4. Step 4: Simplify right side
    72.75x = 7,871.14
  5. Step 5: Solve for x
    x = 7,871.14/72.75
  6. Step 6: Final answer
    x = 108.19

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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.