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Finding the Fourth Proportional to 431.56, 646.80 and 187.80

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Solution

The fourth proportional to 431.56, 646.80 and 187.80 is: 281.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.56 : 646.80 = 187.80 : x
  2. Step 2: Convert to fraction form
    431.56/646.80 = 187.80/x
  3. Step 3: Cross multiply
    431.56x = 646.80 × 187.80
  4. Step 4: Simplify right side
    431.56x = 121,470.60
  5. Step 5: Solve for x
    x = 121,470.60/431.56
  6. Step 6: Final answer
    x = 281.47

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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.