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Finding the Fourth Proportional to 870.45, 1,305.66 and 212.33

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Solution

The fourth proportional to 870.45, 1,305.66 and 212.33 is: 318.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.45 : 1,305.66 = 212.33 : x
  2. Step 2: Convert to fraction form
    870.45/1,305.66 = 212.33/x
  3. Step 3: Cross multiply
    870.45x = 1,305.66 × 212.33
  4. Step 4: Simplify right side
    870.45x = 277,230.79
  5. Step 5: Solve for x
    x = 277,230.79/870.45
  6. Step 6: Final answer
    x = 318.49

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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.