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Finding the Fourth Proportional to 281.30, 421.70 and 189.70

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Solution

The fourth proportional to 281.30, 421.70 and 189.70 is: 284.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    281.30 : 421.70 = 189.70 : x
  2. Step 2: Convert to fraction form
    281.30/421.70 = 189.70/x
  3. Step 3: Cross multiply
    281.30x = 421.70 × 189.70
  4. Step 4: Simplify right side
    281.30x = 79,996.49
  5. Step 5: Solve for x
    x = 79,996.49/281.30
  6. Step 6: Final answer
    x = 284.38

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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.