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Finding the Fourth Proportional to 42.91, 64.60 and 39.13

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Solution

The fourth proportional to 42.91, 64.60 and 39.13 is: 58.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.91 : 64.60 = 39.13 : x
  2. Step 2: Convert to fraction form
    42.91/64.60 = 39.13/x
  3. Step 3: Cross multiply
    42.91x = 64.60 × 39.13
  4. Step 4: Simplify right side
    42.91x = 2,528.06
  5. Step 5: Solve for x
    x = 2,528.06/42.91
  6. Step 6: Final answer
    x = 58.91

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.