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Finding the Fourth Proportional to 285.12, 393.15 and 202.20

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Solution

The fourth proportional to 285.12, 393.15 and 202.20 is: 278.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.12 : 393.15 = 202.20 : x
  2. Step 2: Convert to fraction form
    285.12/393.15 = 202.20/x
  3. Step 3: Cross multiply
    285.12x = 393.15 × 202.20
  4. Step 4: Simplify right side
    285.12x = 79,494.21
  5. Step 5: Solve for x
    x = 79,494.21/285.12
  6. Step 6: Final answer
    x = 278.81

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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.