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Finding the Fourth Proportional to 71.61, 106.79 and 66.75

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Solution

The fourth proportional to 71.61, 106.79 and 66.75 is: 99.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.61 : 106.79 = 66.75 : x
  2. Step 2: Convert to fraction form
    71.61/106.79 = 66.75/x
  3. Step 3: Cross multiply
    71.61x = 106.79 × 66.75
  4. Step 4: Simplify right side
    71.61x = 7,128.23
  5. Step 5: Solve for x
    x = 7,128.23/71.61
  6. Step 6: Final answer
    x = 99.54

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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.