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Finding the Fourth Proportional to 687.09, 948.20 and 392.36

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Solution

The fourth proportional to 687.09, 948.20 and 392.36 is: 541.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.09 : 948.20 = 392.36 : x
  2. Step 2: Convert to fraction form
    687.09/948.20 = 392.36/x
  3. Step 3: Cross multiply
    687.09x = 948.20 × 392.36
  4. Step 4: Simplify right side
    687.09x = 372,029.05
  5. Step 5: Solve for x
    x = 372,029.05/687.09
  6. Step 6: Final answer
    x = 541.45

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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.