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Finding the Fourth Proportional to 870.63, 1,305.40 and 408.50

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Solution

The fourth proportional to 870.63, 1,305.40 and 408.50 is: 612.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.63 : 1,305.40 = 408.50 : x
  2. Step 2: Convert to fraction form
    870.63/1,305.40 = 408.50/x
  3. Step 3: Cross multiply
    870.63x = 1,305.40 × 408.50
  4. Step 4: Simplify right side
    870.63x = 533,255.90
  5. Step 5: Solve for x
    x = 533,255.90/870.63
  6. Step 6: Final answer
    x = 612.49

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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.