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Finding the Fourth Proportional to 828.50, 1,240.70 and 438.86

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Solution

The fourth proportional to 828.50, 1,240.70 and 438.86 is: 657.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.50 : 1,240.70 = 438.86 : x
  2. Step 2: Convert to fraction form
    828.50/1,240.70 = 438.86/x
  3. Step 3: Cross multiply
    828.50x = 1,240.70 × 438.86
  4. Step 4: Simplify right side
    828.50x = 544,493.60
  5. Step 5: Solve for x
    x = 544,493.60/828.50
  6. Step 6: Final answer
    x = 657.20

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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.