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Finding the Fourth Proportional to 820.96, 1,230.56 and 409.28

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Solution

The fourth proportional to 820.96, 1,230.56 and 409.28 is: 613.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.96 : 1,230.56 = 409.28 : x
  2. Step 2: Convert to fraction form
    820.96/1,230.56 = 409.28/x
  3. Step 3: Cross multiply
    820.96x = 1,230.56 × 409.28
  4. Step 4: Simplify right side
    820.96x = 503,641.55
  5. Step 5: Solve for x
    x = 503,641.55/820.96
  6. Step 6: Final answer
    x = 613.48

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1.5x scale

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.