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Finding the Fourth Proportional to 824.80, 1,235.40 and 439.60

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Solution

The fourth proportional to 824.80, 1,235.40 and 439.60 is: 658.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    824.80 : 1,235.40 = 439.60 : x
  2. Step 2: Convert to fraction form
    824.80/1,235.40 = 439.60/x
  3. Step 3: Cross multiply
    824.80x = 1,235.40 × 439.60
  4. Step 4: Simplify right side
    824.80x = 543,081.84
  5. Step 5: Solve for x
    x = 543,081.84/824.80
  6. Step 6: Final answer
    x = 658.44

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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.