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Finding the Fourth Proportional to 390.64, 585.84 and 253.84

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Solution

The fourth proportional to 390.64, 585.84 and 253.84 is: 380.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.64 : 585.84 = 253.84 : x
  2. Step 2: Convert to fraction form
    390.64/585.84 = 253.84/x
  3. Step 3: Cross multiply
    390.64x = 585.84 × 253.84
  4. Step 4: Simplify right side
    390.64x = 148,709.63
  5. Step 5: Solve for x
    x = 148,709.63/390.64
  6. Step 6: Final answer
    x = 380.68

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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.