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Finding the Fourth Proportional to 859.80, 1,290.45 and 656.90

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Solution

The fourth proportional to 859.80, 1,290.45 and 656.90 is: 985.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.80 : 1,290.45 = 656.90 : x
  2. Step 2: Convert to fraction form
    859.80/1,290.45 = 656.90/x
  3. Step 3: Cross multiply
    859.80x = 1,290.45 × 656.90
  4. Step 4: Simplify right side
    859.80x = 847,690.15
  5. Step 5: Solve for x
    x = 847,690.15/859.80
  6. Step 6: Final answer
    x = 985.92

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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.