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Finding the Fourth Proportional to 101.38, 139.89 and 64.57

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Solution

The fourth proportional to 101.38, 139.89 and 64.57 is: 89.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.38 : 139.89 = 64.57 : x
  2. Step 2: Convert to fraction form
    101.38/139.89 = 64.57/x
  3. Step 3: Cross multiply
    101.38x = 139.89 × 64.57
  4. Step 4: Simplify right side
    101.38x = 9,032.70
  5. Step 5: Solve for x
    x = 9,032.70/101.38
  6. Step 6: Final answer
    x = 89.10

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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.