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Finding the Fourth Proportional to 64.29, 88.69 and 39.69

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Solution

The fourth proportional to 64.29, 88.69 and 39.69 is: 54.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.29 : 88.69 = 39.69 : x
  2. Step 2: Convert to fraction form
    64.29/88.69 = 39.69/x
  3. Step 3: Cross multiply
    64.29x = 88.69 × 39.69
  4. Step 4: Simplify right side
    64.29x = 3,520.01
  5. Step 5: Solve for x
    x = 3,520.01/64.29
  6. Step 6: Final answer
    x = 54.75

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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.