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Finding the Fourth Proportional to 820.49, 1,230.42 and 300.40

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Solution

The fourth proportional to 820.49, 1,230.42 and 300.40 is: 450.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.49 : 1,230.42 = 300.40 : x
  2. Step 2: Convert to fraction form
    820.49/1,230.42 = 300.40/x
  3. Step 3: Cross multiply
    820.49x = 1,230.42 × 300.40
  4. Step 4: Simplify right side
    820.49x = 369,618.17
  5. Step 5: Solve for x
    x = 369,618.17/820.49
  6. Step 6: Final answer
    x = 450.48

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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.