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Finding the Fourth Proportional to 685.48, 945.90 and 386.77

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Solution

The fourth proportional to 685.48, 945.90 and 386.77 is: 533.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.48 : 945.90 = 386.77 : x
  2. Step 2: Convert to fraction form
    685.48/945.90 = 386.77/x
  3. Step 3: Cross multiply
    685.48x = 945.90 × 386.77
  4. Step 4: Simplify right side
    685.48x = 365,845.74
  5. Step 5: Solve for x
    x = 365,845.74/685.48
  6. Step 6: Final answer
    x = 533.71

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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.