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Finding the Fourth Proportional to 820.38, 1,228.95 and 666.48

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Solution

The fourth proportional to 820.38, 1,228.95 and 666.48 is: 998.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.38 : 1,228.95 = 666.48 : x
  2. Step 2: Convert to fraction form
    820.38/1,228.95 = 666.48/x
  3. Step 3: Cross multiply
    820.38x = 1,228.95 × 666.48
  4. Step 4: Simplify right side
    820.38x = 819,070.60
  5. Step 5: Solve for x
    x = 819,070.60/820.38
  6. Step 6: Final answer
    x = 998.40

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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.