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Finding the Fourth Proportional to 284.20, 390.90 and 231.08

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Solution

The fourth proportional to 284.20, 390.90 and 231.08 is: 317.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    284.20 : 390.90 = 231.08 : x
  2. Step 2: Convert to fraction form
    284.20/390.90 = 231.08/x
  3. Step 3: Cross multiply
    284.20x = 390.90 × 231.08
  4. Step 4: Simplify right side
    284.20x = 90,329.17
  5. Step 5: Solve for x
    x = 90,329.17/284.20
  6. Step 6: Final answer
    x = 317.84

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.