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Finding the Fourth Proportional to 390.51, 585.81 and 254.43

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Solution

The fourth proportional to 390.51, 585.81 and 254.43 is: 381.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.51 : 585.81 = 254.43 : x
  2. Step 2: Convert to fraction form
    390.51/585.81 = 254.43/x
  3. Step 3: Cross multiply
    390.51x = 585.81 × 254.43
  4. Step 4: Simplify right side
    390.51x = 149,047.64
  5. Step 5: Solve for x
    x = 149,047.64/390.51
  6. Step 6: Final answer
    x = 381.67

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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.