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Finding the Fourth Proportional to 818.85, 1,228.06 and 407.69

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Solution

The fourth proportional to 818.85, 1,228.06 and 407.69 is: 611.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.85 : 1,228.06 = 407.69 : x
  2. Step 2: Convert to fraction form
    818.85/1,228.06 = 407.69/x
  3. Step 3: Cross multiply
    818.85x = 1,228.06 × 407.69
  4. Step 4: Simplify right side
    818.85x = 500,659.60
  5. Step 5: Solve for x
    x = 500,659.60/818.85
  6. Step 6: Final answer
    x = 611.42

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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.