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Finding the Fourth Proportional to 285.51, 428.25 and 90.51

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Solution

The fourth proportional to 285.51, 428.25 and 90.51 is: 135.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.51 : 428.25 = 90.51 : x
  2. Step 2: Convert to fraction form
    285.51/428.25 = 90.51/x
  3. Step 3: Cross multiply
    285.51x = 428.25 × 90.51
  4. Step 4: Simplify right side
    285.51x = 38,760.91
  5. Step 5: Solve for x
    x = 38,760.91/285.51
  6. Step 6: Final answer
    x = 135.76

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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.