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Finding the Fourth Proportional to 830.20, 1,243.76 and 309.88

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Solution

The fourth proportional to 830.20, 1,243.76 and 309.88 is: 464.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    830.20 : 1,243.76 = 309.88 : x
  2. Step 2: Convert to fraction form
    830.20/1,243.76 = 309.88/x
  3. Step 3: Cross multiply
    830.20x = 1,243.76 × 309.88
  4. Step 4: Simplify right side
    830.20x = 385,409.36
  5. Step 5: Solve for x
    x = 385,409.36/830.20
  6. Step 6: Final answer
    x = 464.24

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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.