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Finding the Fourth Proportional to 290.69, 398.75 and 284.61

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Solution

The fourth proportional to 290.69, 398.75 and 284.61 is: 390.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.69 : 398.75 = 284.61 : x
  2. Step 2: Convert to fraction form
    290.69/398.75 = 284.61/x
  3. Step 3: Cross multiply
    290.69x = 398.75 × 284.61
  4. Step 4: Simplify right side
    290.69x = 113,489.11
  5. Step 5: Solve for x
    x = 113,489.11/290.69
  6. Step 6: Final answer
    x = 390.41

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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.