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Finding the Fourth Proportional to 685.49, 945.88 and 386.75

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Solution

The fourth proportional to 685.49, 945.88 and 386.75 is: 533.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.49 : 945.88 = 386.75 : x
  2. Step 2: Convert to fraction form
    685.49/945.88 = 386.75/x
  3. Step 3: Cross multiply
    685.49x = 945.88 × 386.75
  4. Step 4: Simplify right side
    685.49x = 365,817.83
  5. Step 5: Solve for x
    x = 365,817.83/685.49
  6. Step 6: Final answer
    x = 533.66

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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.