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Finding the Fourth Proportional to 687.61, 948.67 and 388.81

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Solution

The fourth proportional to 687.61, 948.67 and 388.81 is: 536.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.61 : 948.67 = 388.81 : x
  2. Step 2: Convert to fraction form
    687.61/948.67 = 388.81/x
  3. Step 3: Cross multiply
    687.61x = 948.67 × 388.81
  4. Step 4: Simplify right side
    687.61x = 368,852.38
  5. Step 5: Solve for x
    x = 368,852.38/687.61
  6. Step 6: Final answer
    x = 536.43

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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.