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Finding the Fourth Proportional to 818.50, 1,228.71 and 385.69

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Solution

The fourth proportional to 818.50, 1,228.71 and 385.69 is: 578.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.50 : 1,228.71 = 385.69 : x
  2. Step 2: Convert to fraction form
    818.50/1,228.71 = 385.69/x
  3. Step 3: Cross multiply
    818.50x = 1,228.71 × 385.69
  4. Step 4: Simplify right side
    818.50x = 473,901.16
  5. Step 5: Solve for x
    x = 473,901.16/818.50
  6. Step 6: Final answer
    x = 578.99

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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.