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Finding the Fourth Proportional to 5.42, 7.49 and 4.20

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Solution

The fourth proportional to 5.42, 7.49 and 4.20 is: 5.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    5.42 : 7.49 = 4.20 : x
  2. Step 2: Convert to fraction form
    5.42/7.49 = 4.20/x
  3. Step 3: Cross multiply
    5.42x = 7.49 × 4.20
  4. Step 4: Simplify right side
    5.42x = 31.44
  5. Step 5: Solve for x
    x = 31.44/5.42
  6. Step 6: Final answer
    x = 5.81

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.