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Finding the Fourth Proportional to 718.16, 991.29 and 485.42

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Solution

The fourth proportional to 718.16, 991.29 and 485.42 is: 670.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.16 : 991.29 = 485.42 : x
  2. Step 2: Convert to fraction form
    718.16/991.29 = 485.42/x
  3. Step 3: Cross multiply
    718.16x = 991.29 × 485.42
  4. Step 4: Simplify right side
    718.16x = 481,187.04
  5. Step 5: Solve for x
    x = 481,187.04/718.16
  6. Step 6: Final answer
    x = 670.03

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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.