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Finding the Fourth Proportional to 809.75, 1,117.19 and 478.28

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Solution

The fourth proportional to 809.75, 1,117.19 and 478.28 is: 659.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.75 : 1,117.19 = 478.28 : x
  2. Step 2: Convert to fraction form
    809.75/1,117.19 = 478.28/x
  3. Step 3: Cross multiply
    809.75x = 1,117.19 × 478.28
  4. Step 4: Simplify right side
    809.75x = 534,327.24
  5. Step 5: Solve for x
    x = 534,327.24/809.75
  6. Step 6: Final answer
    x = 659.87

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Double scale
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1.5x scale

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.