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Finding the Fourth Proportional to 828.16, 1,240.64 and 394.72

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Solution

The fourth proportional to 828.16, 1,240.64 and 394.72 is: 591.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.16 : 1,240.64 = 394.72 : x
  2. Step 2: Convert to fraction form
    828.16/1,240.64 = 394.72/x
  3. Step 3: Cross multiply
    828.16x = 1,240.64 × 394.72
  4. Step 4: Simplify right side
    828.16x = 489,705.42
  5. Step 5: Solve for x
    x = 489,705.42/828.16
  6. Step 6: Final answer
    x = 591.32

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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.