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Finding the Fourth Proportional to 390.94, 539.51 and 216.29

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Solution

The fourth proportional to 390.94, 539.51 and 216.29 is: 298.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.94 : 539.51 = 216.29 : x
  2. Step 2: Convert to fraction form
    390.94/539.51 = 216.29/x
  3. Step 3: Cross multiply
    390.94x = 539.51 × 216.29
  4. Step 4: Simplify right side
    390.94x = 116,690.89
  5. Step 5: Solve for x
    x = 116,690.89/390.94
  6. Step 6: Final answer
    x = 298.49

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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.