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Finding the Fourth Proportional to 808.15, 1,212.35 and 260.15

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Solution

The fourth proportional to 808.15, 1,212.35 and 260.15 is: 390.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.15 : 1,212.35 = 260.15 : x
  2. Step 2: Convert to fraction form
    808.15/1,212.35 = 260.15/x
  3. Step 3: Cross multiply
    808.15x = 1,212.35 × 260.15
  4. Step 4: Simplify right side
    808.15x = 315,394.58
  5. Step 5: Solve for x
    x = 315,394.58/808.15
  6. Step 6: Final answer
    x = 390.27

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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.