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Finding the Fourth Proportional to 718.09, 990.94 and 399.03

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Solution

The fourth proportional to 718.09, 990.94 and 399.03 is: 550.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.09 : 990.94 = 399.03 : x
  2. Step 2: Convert to fraction form
    718.09/990.94 = 399.03/x
  3. Step 3: Cross multiply
    718.09x = 990.94 × 399.03
  4. Step 4: Simplify right side
    718.09x = 395,417.27
  5. Step 5: Solve for x
    x = 395,417.27/718.09
  6. Step 6: Final answer
    x = 550.66

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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.