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Finding the Fourth Proportional to 291.90, 399.26 and 284.70

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Solution

The fourth proportional to 291.90, 399.26 and 284.70 is: 389.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    291.90 : 399.26 = 284.70 : x
  2. Step 2: Convert to fraction form
    291.90/399.26 = 284.70/x
  3. Step 3: Cross multiply
    291.90x = 399.26 × 284.70
  4. Step 4: Simplify right side
    291.90x = 113,667.90
  5. Step 5: Solve for x
    x = 113,667.90/291.90
  6. Step 6: Final answer
    x = 389.41

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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.