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Finding the Fourth Proportional to 979.21, 1,468.63 and 285.72

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Solution

The fourth proportional to 979.21, 1,468.63 and 285.72 is: 428.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    979.21 : 1,468.63 = 285.72 : x
  2. Step 2: Convert to fraction form
    979.21/1,468.63 = 285.72/x
  3. Step 3: Cross multiply
    979.21x = 1,468.63 × 285.72
  4. Step 4: Simplify right side
    979.21x = 419,616.96
  5. Step 5: Solve for x
    x = 419,616.96/979.21
  6. Step 6: Final answer
    x = 428.53

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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.