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Finding the Fourth Proportional to 771.80, 1,157.85 and 442.40

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Solution

The fourth proportional to 771.80, 1,157.85 and 442.40 is: 663.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    771.80 : 1,157.85 = 442.40 : x
  2. Step 2: Convert to fraction form
    771.80/1,157.85 = 442.40/x
  3. Step 3: Cross multiply
    771.80x = 1,157.85 × 442.40
  4. Step 4: Simplify right side
    771.80x = 512,227.05
  5. Step 5: Solve for x
    x = 512,227.05/771.80
  6. Step 6: Final answer
    x = 663.68

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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.