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Finding the Fourth Proportional to 287.30, 431.40 and 165.80

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Solution

The fourth proportional to 287.30, 431.40 and 165.80 is: 248.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.30 : 431.40 = 165.80 : x
  2. Step 2: Convert to fraction form
    287.30/431.40 = 165.80/x
  3. Step 3: Cross multiply
    287.30x = 431.40 × 165.80
  4. Step 4: Simplify right side
    287.30x = 71,526.12
  5. Step 5: Solve for x
    x = 71,526.12/287.30
  6. Step 6: Final answer
    x = 248.96

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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.