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Finding the Fourth Proportional to 439.40, 659.94 and 257.16

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Solution

The fourth proportional to 439.40, 659.94 and 257.16 is: 386.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.40 : 659.94 = 257.16 : x
  2. Step 2: Convert to fraction form
    439.40/659.94 = 257.16/x
  3. Step 3: Cross multiply
    439.40x = 659.94 × 257.16
  4. Step 4: Simplify right side
    439.40x = 169,710.17
  5. Step 5: Solve for x
    x = 169,710.17/439.40
  6. Step 6: Final answer
    x = 386.23

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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.