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Finding the Fourth Proportional to 809.58, 1,112.38 and 643.50

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Solution

The fourth proportional to 809.58, 1,112.38 and 643.50 is: 884.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.58 : 1,112.38 = 643.50 : x
  2. Step 2: Convert to fraction form
    809.58/1,112.38 = 643.50/x
  3. Step 3: Cross multiply
    809.58x = 1,112.38 × 643.50
  4. Step 4: Simplify right side
    809.58x = 715,817.14
  5. Step 5: Solve for x
    x = 715,817.14/809.58
  6. Step 6: Final answer
    x = 884.19

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.