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Finding the Fourth Proportional to 799.15, 1,199.40 and 312.55

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Solution

The fourth proportional to 799.15, 1,199.40 and 312.55 is: 469.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    799.15 : 1,199.40 = 312.55 : x
  2. Step 2: Convert to fraction form
    799.15/1,199.40 = 312.55/x
  3. Step 3: Cross multiply
    799.15x = 1,199.40 × 312.55
  4. Step 4: Simplify right side
    799.15x = 374,872.47
  5. Step 5: Solve for x
    x = 374,872.47/799.15
  6. Step 6: Final answer
    x = 469.09

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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.