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Finding the Fourth Proportional to 285.72, 393.96 and 220.08

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Solution

The fourth proportional to 285.72, 393.96 and 220.08 is: 303.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.72 : 393.96 = 220.08 : x
  2. Step 2: Convert to fraction form
    285.72/393.96 = 220.08/x
  3. Step 3: Cross multiply
    285.72x = 393.96 × 220.08
  4. Step 4: Simplify right side
    285.72x = 86,702.72
  5. Step 5: Solve for x
    x = 86,702.72/285.72
  6. Step 6: Final answer
    x = 303.45

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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.