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Finding the Fourth Proportional to 319.92, 438.66 and 288.72

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Solution

The fourth proportional to 319.92, 438.66 and 288.72 is: 395.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.92 : 438.66 = 288.72 : x
  2. Step 2: Convert to fraction form
    319.92/438.66 = 288.72/x
  3. Step 3: Cross multiply
    319.92x = 438.66 × 288.72
  4. Step 4: Simplify right side
    319.92x = 126,649.92
  5. Step 5: Solve for x
    x = 126,649.92/319.92
  6. Step 6: Final answer
    x = 395.88

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.