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Finding the Fourth Proportional to 685.68, 945.66 and 499.80

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Solution

The fourth proportional to 685.68, 945.66 and 499.80 is: 689.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.68 : 945.66 = 499.80 : x
  2. Step 2: Convert to fraction form
    685.68/945.66 = 499.80/x
  3. Step 3: Cross multiply
    685.68x = 945.66 × 499.80
  4. Step 4: Simplify right side
    685.68x = 472,640.87
  5. Step 5: Solve for x
    x = 472,640.87/685.68
  6. Step 6: Final answer
    x = 689.30

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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.