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Finding the Fourth Proportional to 42.68, 64.33 and 39.80

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Solution

The fourth proportional to 42.68, 64.33 and 39.80 is: 59.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.68 : 64.33 = 39.80 : x
  2. Step 2: Convert to fraction form
    42.68/64.33 = 39.80/x
  3. Step 3: Cross multiply
    42.68x = 64.33 × 39.80
  4. Step 4: Simplify right side
    42.68x = 2,560.33
  5. Step 5: Solve for x
    x = 2,560.33/42.68
  6. Step 6: Final answer
    x = 59.99

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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.