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Finding the Fourth Proportional to 847.78, 1,271.84 and 385.78

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Solution

The fourth proportional to 847.78, 1,271.84 and 385.78 is: 578.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    847.78 : 1,271.84 = 385.78 : x
  2. Step 2: Convert to fraction form
    847.78/1,271.84 = 385.78/x
  3. Step 3: Cross multiply
    847.78x = 1,271.84 × 385.78
  4. Step 4: Simplify right side
    847.78x = 490,650.44
  5. Step 5: Solve for x
    x = 490,650.44/847.78
  6. Step 6: Final answer
    x = 578.75

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1.5x scale

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.