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Finding the Fourth Proportional to 808.70, 1,213.25 and 260.91

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Solution

The fourth proportional to 808.70, 1,213.25 and 260.91 is: 391.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.70 : 1,213.25 = 260.91 : x
  2. Step 2: Convert to fraction form
    808.70/1,213.25 = 260.91/x
  3. Step 3: Cross multiply
    808.70x = 1,213.25 × 260.91
  4. Step 4: Simplify right side
    808.70x = 316,547.75
  5. Step 5: Solve for x
    x = 316,547.75/808.70
  6. Step 6: Final answer
    x = 391.43

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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.