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Finding the Fourth Proportional to 820.08, 1,228.88 and 386.16

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Solution

The fourth proportional to 820.08, 1,228.88 and 386.16 is: 578.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.08 : 1,228.88 = 386.16 : x
  2. Step 2: Convert to fraction form
    820.08/1,228.88 = 386.16/x
  3. Step 3: Cross multiply
    820.08x = 1,228.88 × 386.16
  4. Step 4: Simplify right side
    820.08x = 474,544.30
  5. Step 5: Solve for x
    x = 474,544.30/820.08
  6. Step 6: Final answer
    x = 578.66

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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.