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Finding the Fourth Proportional to 320.40, 439.26 and 318

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Solution

The fourth proportional to 320.40, 439.26 and 318 is: 435.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.40 : 439.26 = 318 : x
  2. Step 2: Convert to fraction form
    320.40/439.26 = 318/x
  3. Step 3: Cross multiply
    320.40x = 439.26 × 318
  4. Step 4: Simplify right side
    320.40x = 139,684.68
  5. Step 5: Solve for x
    x = 139,684.68/320.40
  6. Step 6: Final answer
    x = 435.97

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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.