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Finding the Fourth Proportional to 828.21, 1,142.95 and 455.21

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Solution

The fourth proportional to 828.21, 1,142.95 and 455.21 is: 628.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.21 : 1,142.95 = 455.21 : x
  2. Step 2: Convert to fraction form
    828.21/1,142.95 = 455.21/x
  3. Step 3: Cross multiply
    828.21x = 1,142.95 × 455.21
  4. Step 4: Simplify right side
    828.21x = 520,282.27
  5. Step 5: Solve for x
    x = 520,282.27/828.21
  6. Step 6: Final answer
    x = 628.20

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.