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Finding the Fourth Proportional to 839.30, 1,157.40 and 559.35

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Solution

The fourth proportional to 839.30, 1,157.40 and 559.35 is: 771.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.30 : 1,157.40 = 559.35 : x
  2. Step 2: Convert to fraction form
    839.30/1,157.40 = 559.35/x
  3. Step 3: Cross multiply
    839.30x = 1,157.40 × 559.35
  4. Step 4: Simplify right side
    839.30x = 647,391.69
  5. Step 5: Solve for x
    x = 647,391.69/839.30
  6. Step 6: Final answer
    x = 771.35

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.