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Finding the Fourth Proportional to 290.34, 398.08 and 285.15

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Solution

The fourth proportional to 290.34, 398.08 and 285.15 is: 390.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.34 : 398.08 = 285.15 : x
  2. Step 2: Convert to fraction form
    290.34/398.08 = 285.15/x
  3. Step 3: Cross multiply
    290.34x = 398.08 × 285.15
  4. Step 4: Simplify right side
    290.34x = 113,509.10
  5. Step 5: Solve for x
    x = 113,509.10/290.34
  6. Step 6: Final answer
    x = 390.95

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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.