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Finding the Fourth Proportional to 285.87, 428.64 and 155.78

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Solution

The fourth proportional to 285.87, 428.64 and 155.78 is: 233.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.87 : 428.64 = 155.78 : x
  2. Step 2: Convert to fraction form
    285.87/428.64 = 155.78/x
  3. Step 3: Cross multiply
    285.87x = 428.64 × 155.78
  4. Step 4: Simplify right side
    285.87x = 66,771.40
  5. Step 5: Solve for x
    x = 66,771.40/285.87
  6. Step 6: Final answer
    x = 233.57

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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.