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Finding the Fourth Proportional to 818.61, 1,228.57 and 407.63

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Solution

The fourth proportional to 818.61, 1,228.57 and 407.63 is: 611.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.61 : 1,228.57 = 407.63 : x
  2. Step 2: Convert to fraction form
    818.61/1,228.57 = 407.63/x
  3. Step 3: Cross multiply
    818.61x = 1,228.57 × 407.63
  4. Step 4: Simplify right side
    818.61x = 500,804.04
  5. Step 5: Solve for x
    x = 500,804.04/818.61
  6. Step 6: Final answer
    x = 611.78

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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.