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Finding the Fourth Proportional to 42.80, 63.84 and 40.28

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Solution

The fourth proportional to 42.80, 63.84 and 40.28 is: 60.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.80 : 63.84 = 40.28 : x
  2. Step 2: Convert to fraction form
    42.80/63.84 = 40.28/x
  3. Step 3: Cross multiply
    42.80x = 63.84 × 40.28
  4. Step 4: Simplify right side
    42.80x = 2,571.48
  5. Step 5: Solve for x
    x = 2,571.48/42.80
  6. Step 6: Final answer
    x = 60.08

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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.