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Finding the Fourth Proportional to 869.95, 1,305.20 and 407.71

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Solution

The fourth proportional to 869.95, 1,305.20 and 407.71 is: 611.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.95 : 1,305.20 = 407.71 : x
  2. Step 2: Convert to fraction form
    869.95/1,305.20 = 407.71/x
  3. Step 3: Cross multiply
    869.95x = 1,305.20 × 407.71
  4. Step 4: Simplify right side
    869.95x = 532,143.09
  5. Step 5: Solve for x
    x = 532,143.09/869.95
  6. Step 6: Final answer
    x = 611.69

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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.