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Finding the Fourth Proportional to 71.28, 106.19 and 66.60

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Solution

The fourth proportional to 71.28, 106.19 and 66.60 is: 99.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.28 : 106.19 = 66.60 : x
  2. Step 2: Convert to fraction form
    71.28/106.19 = 66.60/x
  3. Step 3: Cross multiply
    71.28x = 106.19 × 66.60
  4. Step 4: Simplify right side
    71.28x = 7,072.25
  5. Step 5: Solve for x
    x = 7,072.25/71.28
  6. Step 6: Final answer
    x = 99.22

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.