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Finding the Fourth Proportional to 101.05, 139.42 and 64.21

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Solution

The fourth proportional to 101.05, 139.42 and 64.21 is: 88.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.05 : 139.42 = 64.21 : x
  2. Step 2: Convert to fraction form
    101.05/139.42 = 64.21/x
  3. Step 3: Cross multiply
    101.05x = 139.42 × 64.21
  4. Step 4: Simplify right side
    101.05x = 8,952.16
  5. Step 5: Solve for x
    x = 8,952.16/101.05
  6. Step 6: Final answer
    x = 88.60

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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.