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Finding the Fourth Proportional to 101.72, 140.32 and 64.81

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Solution

The fourth proportional to 101.72, 140.32 and 64.81 is: 89.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.72 : 140.32 = 64.81 : x
  2. Step 2: Convert to fraction form
    101.72/140.32 = 64.81/x
  3. Step 3: Cross multiply
    101.72x = 140.32 × 64.81
  4. Step 4: Simplify right side
    101.72x = 9,094.14
  5. Step 5: Solve for x
    x = 9,094.14/101.72
  6. Step 6: Final answer
    x = 89.40

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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.