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Finding the Fourth Proportional to 690.91, 1,035.54 and 300.78

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Solution

The fourth proportional to 690.91, 1,035.54 and 300.78 is: 450.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.91 : 1,035.54 = 300.78 : x
  2. Step 2: Convert to fraction form
    690.91/1,035.54 = 300.78/x
  3. Step 3: Cross multiply
    690.91x = 1,035.54 × 300.78
  4. Step 4: Simplify right side
    690.91x = 311,469.72
  5. Step 5: Solve for x
    x = 311,469.72/690.91
  6. Step 6: Final answer
    x = 450.81

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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.