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Finding the Fourth Proportional to 808.68, 1,212.90 and 260.79

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Solution

The fourth proportional to 808.68, 1,212.90 and 260.79 is: 391.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.68 : 1,212.90 = 260.79 : x
  2. Step 2: Convert to fraction form
    808.68/1,212.90 = 260.79/x
  3. Step 3: Cross multiply
    808.68x = 1,212.90 × 260.79
  4. Step 4: Simplify right side
    808.68x = 316,312.19
  5. Step 5: Solve for x
    x = 316,312.19/808.68
  6. Step 6: Final answer
    x = 391.15

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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.