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Finding the Fourth Proportional to 42.87, 64.00 and 39.66

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Solution

The fourth proportional to 42.87, 64.00 and 39.66 is: 59.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.87 : 64.00 = 39.66 : x
  2. Step 2: Convert to fraction form
    42.87/64.00 = 39.66/x
  3. Step 3: Cross multiply
    42.87x = 64.00 × 39.66
  4. Step 4: Simplify right side
    42.87x = 2,537.72
  5. Step 5: Solve for x
    x = 2,537.72/42.87
  6. Step 6: Final answer
    x = 59.20

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.