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Finding the Fourth Proportional to 319.71, 440.57 and 257.45

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Solution

The fourth proportional to 319.71, 440.57 and 257.45 is: 354.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.71 : 440.57 = 257.45 : x
  2. Step 2: Convert to fraction form
    319.71/440.57 = 257.45/x
  3. Step 3: Cross multiply
    319.71x = 440.57 × 257.45
  4. Step 4: Simplify right side
    319.71x = 113,421.26
  5. Step 5: Solve for x
    x = 113,421.26/319.71
  6. Step 6: Final answer
    x = 354.76

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.