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Finding the Fourth Proportional to 393.05, 542.42 and 218.40

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Solution

The fourth proportional to 393.05, 542.42 and 218.40 is: 301.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    393.05 : 542.42 = 218.40 : x
  2. Step 2: Convert to fraction form
    393.05/542.42 = 218.40/x
  3. Step 3: Cross multiply
    393.05x = 542.42 × 218.40
  4. Step 4: Simplify right side
    393.05x = 118,462.22
  5. Step 5: Solve for x
    x = 118,462.22/393.05
  6. Step 6: Final answer
    x = 301.39

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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.