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Finding the Fourth Proportional to 847.40, 1,271.21 and 385.29

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Solution

The fourth proportional to 847.40, 1,271.21 and 385.29 is: 577.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    847.40 : 1,271.21 = 385.29 : x
  2. Step 2: Convert to fraction form
    847.40/1,271.21 = 385.29/x
  3. Step 3: Cross multiply
    847.40x = 1,271.21 × 385.29
  4. Step 4: Simplify right side
    847.40x = 489,782.57
  5. Step 5: Solve for x
    x = 489,782.57/847.40
  6. Step 6: Final answer
    x = 577.99

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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.