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Finding the Fourth Proportional to 685.50, 945.92 and 386.72

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Solution

The fourth proportional to 685.50, 945.92 and 386.72 is: 533.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.50 : 945.92 = 386.72 : x
  2. Step 2: Convert to fraction form
    685.50/945.92 = 386.72/x
  3. Step 3: Cross multiply
    685.50x = 945.92 × 386.72
  4. Step 4: Simplify right side
    685.50x = 365,809.99
  5. Step 5: Solve for x
    x = 365,809.99/685.50
  6. Step 6: Final answer
    x = 533.64

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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.