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Finding the Fourth Proportional to 291.80, 399.80 and 287.76

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Solution

The fourth proportional to 291.80, 399.80 and 287.76 is: 394.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    291.80 : 399.80 = 287.76 : x
  2. Step 2: Convert to fraction form
    291.80/399.80 = 287.76/x
  3. Step 3: Cross multiply
    291.80x = 399.80 × 287.76
  4. Step 4: Simplify right side
    291.80x = 115,046.45
  5. Step 5: Solve for x
    x = 115,046.45/291.80
  6. Step 6: Final answer
    x = 394.26

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.