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Finding the Fourth Proportional to 718.38, 991.36 and 399.37

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Solution

The fourth proportional to 718.38, 991.36 and 399.37 is: 551.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.38 : 991.36 = 399.37 : x
  2. Step 2: Convert to fraction form
    718.38/991.36 = 399.37/x
  3. Step 3: Cross multiply
    718.38x = 991.36 × 399.37
  4. Step 4: Simplify right side
    718.38x = 395,919.44
  5. Step 5: Solve for x
    x = 395,919.44/718.38
  6. Step 6: Final answer
    x = 551.13

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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.