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Finding the Fourth Proportional to 287.31, 430.64 and 218.63

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Solution

The fourth proportional to 287.31, 430.64 and 218.63 is: 327.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.31 : 430.64 = 218.63 : x
  2. Step 2: Convert to fraction form
    287.31/430.64 = 218.63/x
  3. Step 3: Cross multiply
    287.31x = 430.64 × 218.63
  4. Step 4: Simplify right side
    287.31x = 94,147.58
  5. Step 5: Solve for x
    x = 94,147.58/287.31
  6. Step 6: Final answer
    x = 327.69

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.