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Finding the Fourth Proportional to 101.47, 139.98 and 79.60

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Solution

The fourth proportional to 101.47, 139.98 and 79.60 is: 109.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.47 : 139.98 = 79.60 : x
  2. Step 2: Convert to fraction form
    101.47/139.98 = 79.60/x
  3. Step 3: Cross multiply
    101.47x = 139.98 × 79.60
  4. Step 4: Simplify right side
    101.47x = 11,142.41
  5. Step 5: Solve for x
    x = 11,142.41/101.47
  6. Step 6: Final answer
    x = 109.81

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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.