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Finding the Fourth Proportional to 64.76, 89.34 and 61.71

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Solution

The fourth proportional to 64.76, 89.34 and 61.71 is: 85.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.76 : 89.34 = 61.71 : x
  2. Step 2: Convert to fraction form
    64.76/89.34 = 61.71/x
  3. Step 3: Cross multiply
    64.76x = 89.34 × 61.71
  4. Step 4: Simplify right side
    64.76x = 5,513.17
  5. Step 5: Solve for x
    x = 5,513.17/64.76
  6. Step 6: Final answer
    x = 85.14

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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.