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Finding the Fourth Proportional to 390.57, 585.78 and 286.89

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Solution

The fourth proportional to 390.57, 585.78 and 286.89 is: 430.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.57 : 585.78 = 286.89 : x
  2. Step 2: Convert to fraction form
    390.57/585.78 = 286.89/x
  3. Step 3: Cross multiply
    390.57x = 585.78 × 286.89
  4. Step 4: Simplify right side
    390.57x = 168,054.42
  5. Step 5: Solve for x
    x = 168,054.42/390.57
  6. Step 6: Final answer
    x = 430.28

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.