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Finding the Fourth Proportional to 101.20, 139.70 and 64.36

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Solution

The fourth proportional to 101.20, 139.70 and 64.36 is: 88.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.20 : 139.70 = 64.36 : x
  2. Step 2: Convert to fraction form
    101.20/139.70 = 64.36/x
  3. Step 3: Cross multiply
    101.20x = 139.70 × 64.36
  4. Step 4: Simplify right side
    101.20x = 8,991.09
  5. Step 5: Solve for x
    x = 8,991.09/101.20
  6. Step 6: Final answer
    x = 88.84

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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.