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Finding the Fourth Proportional to 870.68, 1,305.63 and 408.59

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Solution

The fourth proportional to 870.68, 1,305.63 and 408.59 is: 612.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.68 : 1,305.63 = 408.59 : x
  2. Step 2: Convert to fraction form
    870.68/1,305.63 = 408.59/x
  3. Step 3: Cross multiply
    870.68x = 1,305.63 × 408.59
  4. Step 4: Simplify right side
    870.68x = 533,470.63
  5. Step 5: Solve for x
    x = 533,470.63/870.68
  6. Step 6: Final answer
    x = 612.71

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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.