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Finding the Fourth Proportional to 285.90, 428.31 and 189.51

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Solution

The fourth proportional to 285.90, 428.31 and 189.51 is: 283.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.90 : 428.31 = 189.51 : x
  2. Step 2: Convert to fraction form
    285.90/428.31 = 189.51/x
  3. Step 3: Cross multiply
    285.90x = 428.31 × 189.51
  4. Step 4: Simplify right side
    285.90x = 81,169.03
  5. Step 5: Solve for x
    x = 81,169.03/285.90
  6. Step 6: Final answer
    x = 283.91

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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.