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Finding the Fourth Proportional to 101.71, 140.40 and 77.21

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Solution

The fourth proportional to 101.71, 140.40 and 77.21 is: 106.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.71 : 140.40 = 77.21 : x
  2. Step 2: Convert to fraction form
    101.71/140.40 = 77.21/x
  3. Step 3: Cross multiply
    101.71x = 140.40 × 77.21
  4. Step 4: Simplify right side
    101.71x = 10,840.11
  5. Step 5: Solve for x
    x = 10,840.11/101.71
  6. Step 6: Final answer
    x = 106.58

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.