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Finding the Fourth Proportional to 799.78, 1,199.91 and 312.97

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Solution

The fourth proportional to 799.78, 1,199.91 and 312.97 is: 469.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    799.78 : 1,199.91 = 312.97 : x
  2. Step 2: Convert to fraction form
    799.78/1,199.91 = 312.97/x
  3. Step 3: Cross multiply
    799.78x = 1,199.91 × 312.97
  4. Step 4: Simplify right side
    799.78x = 375,535.83
  5. Step 5: Solve for x
    x = 375,535.83/799.78
  6. Step 6: Final answer
    x = 469.55

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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.