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Finding the Fourth Proportional to 775.06, 1,161.78 and 287.80

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Solution

The fourth proportional to 775.06, 1,161.78 and 287.80 is: 431.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    775.06 : 1,161.78 = 287.80 : x
  2. Step 2: Convert to fraction form
    775.06/1,161.78 = 287.80/x
  3. Step 3: Cross multiply
    775.06x = 1,161.78 × 287.80
  4. Step 4: Simplify right side
    775.06x = 334,360.28
  5. Step 5: Solve for x
    x = 334,360.28/775.06
  6. Step 6: Final answer
    x = 431.40

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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.