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Finding the Fourth Proportional to 687.27, 948.40 and 388.53

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Solution

The fourth proportional to 687.27, 948.40 and 388.53 is: 536.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.27 : 948.40 = 388.53 : x
  2. Step 2: Convert to fraction form
    687.27/948.40 = 388.53/x
  3. Step 3: Cross multiply
    687.27x = 948.40 × 388.53
  4. Step 4: Simplify right side
    687.27x = 368,478.78
  5. Step 5: Solve for x
    x = 368,478.78/687.27
  6. Step 6: Final answer
    x = 536.15

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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.