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Finding the Fourth Proportional to 871.40, 1,307.10 and 323.70

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Solution

The fourth proportional to 871.40, 1,307.10 and 323.70 is: 485.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.40 : 1,307.10 = 323.70 : x
  2. Step 2: Convert to fraction form
    871.40/1,307.10 = 323.70/x
  3. Step 3: Cross multiply
    871.40x = 1,307.10 × 323.70
  4. Step 4: Simplify right side
    871.40x = 423,108.27
  5. Step 5: Solve for x
    x = 423,108.27/871.40
  6. Step 6: Final answer
    x = 485.55

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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.