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Finding the Fourth Proportional to 71.21, 106.80 and 30.60

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Solution

The fourth proportional to 71.21, 106.80 and 30.60 is: 45.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.21 : 106.80 = 30.60 : x
  2. Step 2: Convert to fraction form
    71.21/106.80 = 30.60/x
  3. Step 3: Cross multiply
    71.21x = 106.80 × 30.60
  4. Step 4: Simplify right side
    71.21x = 3,268.08
  5. Step 5: Solve for x
    x = 3,268.08/71.21
  6. Step 6: Final answer
    x = 45.90

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.