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Finding the Fourth Proportional to 390.42, 585.06 and 243.72

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Solution

The fourth proportional to 390.42, 585.06 and 243.72 is: 365.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.42 : 585.06 = 243.72 : x
  2. Step 2: Convert to fraction form
    390.42/585.06 = 243.72/x
  3. Step 3: Cross multiply
    390.42x = 585.06 × 243.72
  4. Step 4: Simplify right side
    390.42x = 142,590.82
  5. Step 5: Solve for x
    x = 142,590.82/390.42
  6. Step 6: Final answer
    x = 365.22

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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.