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Finding the Fourth Proportional to 101.21, 139.23 and 79.34

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Solution

The fourth proportional to 101.21, 139.23 and 79.34 is: 109.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.21 : 139.23 = 79.34 : x
  2. Step 2: Convert to fraction form
    101.21/139.23 = 79.34/x
  3. Step 3: Cross multiply
    101.21x = 139.23 × 79.34
  4. Step 4: Simplify right side
    101.21x = 11,045.81
  5. Step 5: Solve for x
    x = 11,045.81/101.21
  6. Step 6: Final answer
    x = 109.14

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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.