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Finding the Fourth Proportional to 389.21, 536.66 and 290.79

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Solution

The fourth proportional to 389.21, 536.66 and 290.79 is: 400.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.21 : 536.66 = 290.79 : x
  2. Step 2: Convert to fraction form
    389.21/536.66 = 290.79/x
  3. Step 3: Cross multiply
    389.21x = 536.66 × 290.79
  4. Step 4: Simplify right side
    389.21x = 156,053.91
  5. Step 5: Solve for x
    x = 156,053.91/389.21
  6. Step 6: Final answer
    x = 400.95

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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.