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Finding the Fourth Proportional to 28.40, 42.38 and 28.22

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Solution

The fourth proportional to 28.40, 42.38 and 28.22 is: 42.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.40 : 42.38 = 28.22 : x
  2. Step 2: Convert to fraction form
    28.40/42.38 = 28.22/x
  3. Step 3: Cross multiply
    28.40x = 42.38 × 28.22
  4. Step 4: Simplify right side
    28.40x = 1,195.82
  5. Step 5: Solve for x
    x = 1,195.82/28.40
  6. Step 6: Final answer
    x = 42.11

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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.