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Finding the Fourth Proportional to 285.25, 428 and 280.63

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Solution

The fourth proportional to 285.25, 428 and 280.63 is: 421.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.25 : 428 = 280.63 : x
  2. Step 2: Convert to fraction form
    285.25/428 = 280.63/x
  3. Step 3: Cross multiply
    285.25x = 428 × 280.63
  4. Step 4: Simplify right side
    285.25x = 120,109.64
  5. Step 5: Solve for x
    x = 120,109.64/285.25
  6. Step 6: Final answer
    x = 421.07

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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.