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Finding the Fourth Proportional to 4.80, 7.20 and 1.42

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Solution

The fourth proportional to 4.80, 7.20 and 1.42 is: 2.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    4.80 : 7.20 = 1.42 : x
  2. Step 2: Convert to fraction form
    4.80/7.20 = 1.42/x
  3. Step 3: Cross multiply
    4.80x = 7.20 × 1.42
  4. Step 4: Simplify right side
    4.80x = 10.22
  5. Step 5: Solve for x
    x = 10.22/4.80
  6. Step 6: Final answer
    x = 2.13

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.