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Finding the Fourth Proportional to 405.72, 559.28 and 318.24

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Solution

The fourth proportional to 405.72, 559.28 and 318.24 is: 438.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.72 : 559.28 = 318.24 : x
  2. Step 2: Convert to fraction form
    405.72/559.28 = 318.24/x
  3. Step 3: Cross multiply
    405.72x = 559.28 × 318.24
  4. Step 4: Simplify right side
    405.72x = 177,985.27
  5. Step 5: Solve for x
    x = 177,985.27/405.72
  6. Step 6: Final answer
    x = 438.69

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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.