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Finding the Fourth Proportional to 101.40, 139.90 and 64.57

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Solution

The fourth proportional to 101.40, 139.90 and 64.57 is: 89.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.40 : 139.90 = 64.57 : x
  2. Step 2: Convert to fraction form
    101.40/139.90 = 64.57/x
  3. Step 3: Cross multiply
    101.40x = 139.90 × 64.57
  4. Step 4: Simplify right side
    101.40x = 9,033.34
  5. Step 5: Solve for x
    x = 9,033.34/101.40
  6. Step 6: Final answer
    x = 89.09

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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.