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Finding the Fourth Proportional to 313, 431.40 and 280.33

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Solution

The fourth proportional to 313, 431.40 and 280.33 is: 386.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    313 : 431.40 = 280.33 : x
  2. Step 2: Convert to fraction form
    313/431.40 = 280.33/x
  3. Step 3: Cross multiply
    313x = 431.40 × 280.33
  4. Step 4: Simplify right side
    313x = 120,934.36
  5. Step 5: Solve for x
    x = 120,934.36/313
  6. Step 6: Final answer
    x = 386.37

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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.