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Finding the Fourth Proportional to 285.65, 428.39 and 80.22

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Solution

The fourth proportional to 285.65, 428.39 and 80.22 is: 120.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.65 : 428.39 = 80.22 : x
  2. Step 2: Convert to fraction form
    285.65/428.39 = 80.22/x
  3. Step 3: Cross multiply
    285.65x = 428.39 × 80.22
  4. Step 4: Simplify right side
    285.65x = 34,367.40
  5. Step 5: Solve for x
    x = 34,367.40/285.65
  6. Step 6: Final answer
    x = 120.31

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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.