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Finding the Fourth Proportional to 870.10, 1,305.05 and 220.79

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Solution

The fourth proportional to 870.10, 1,305.05 and 220.79 is: 331.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.10 : 1,305.05 = 220.79 : x
  2. Step 2: Convert to fraction form
    870.10/1,305.05 = 220.79/x
  3. Step 3: Cross multiply
    870.10x = 1,305.05 × 220.79
  4. Step 4: Simplify right side
    870.10x = 288,144.15
  5. Step 5: Solve for x
    x = 288,144.15/870.10
  6. Step 6: Final answer
    x = 331.16

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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.