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Finding the Fourth Proportional to 816.10, 1,221.99 and 430.18

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Solution

The fourth proportional to 816.10, 1,221.99 and 430.18 is: 644.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    816.10 : 1,221.99 = 430.18 : x
  2. Step 2: Convert to fraction form
    816.10/1,221.99 = 430.18/x
  3. Step 3: Cross multiply
    816.10x = 1,221.99 × 430.18
  4. Step 4: Simplify right side
    816.10x = 525,675.66
  5. Step 5: Solve for x
    x = 525,675.66/816.10
  6. Step 6: Final answer
    x = 644.13

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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.