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Finding the Fourth Proportional to 718.80, 991.89 and 424.05

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Solution

The fourth proportional to 718.80, 991.89 and 424.05 is: 585.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.80 : 991.89 = 424.05 : x
  2. Step 2: Convert to fraction form
    718.80/991.89 = 424.05/x
  3. Step 3: Cross multiply
    718.80x = 991.89 × 424.05
  4. Step 4: Simplify right side
    718.80x = 420,610.95
  5. Step 5: Solve for x
    x = 420,610.95/718.80
  6. Step 6: Final answer
    x = 585.16

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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.