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Finding the Fourth Proportional to 828.72, 1,243.01 and 212.45

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Solution

The fourth proportional to 828.72, 1,243.01 and 212.45 is: 318.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.72 : 1,243.01 = 212.45 : x
  2. Step 2: Convert to fraction form
    828.72/1,243.01 = 212.45/x
  3. Step 3: Cross multiply
    828.72x = 1,243.01 × 212.45
  4. Step 4: Simplify right side
    828.72x = 264,070.20
  5. Step 5: Solve for x
    x = 264,070.20/828.72
  6. Step 6: Final answer
    x = 318.65

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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.