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Finding the Fourth Proportional to 1,289.85, 1,937.36 and 770.87

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Solution

The fourth proportional to 1,289.85, 1,937.36 and 770.87 is: 1,157.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.85 : 1,937.36 = 770.87 : x
  2. Step 2: Convert to fraction form
    1,289.85/1,937.36 = 770.87/x
  3. Step 3: Cross multiply
    1,289.85x = 1,937.36 × 770.87
  4. Step 4: Simplify right side
    1,289.85x = 1,493,439.16
  5. Step 5: Solve for x
    x = 1,493,439.16/1,289.85
  6. Step 6: Final answer
    x = 1,157.84

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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.