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Finding the Fourth Proportional to 718.80, 991.40 and 608.88

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Solution

The fourth proportional to 718.80, 991.40 and 608.88 is: 839.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.80 : 991.40 = 608.88 : x
  2. Step 2: Convert to fraction form
    718.80/991.40 = 608.88/x
  3. Step 3: Cross multiply
    718.80x = 991.40 × 608.88
  4. Step 4: Simplify right side
    718.80x = 603,643.63
  5. Step 5: Solve for x
    x = 603,643.63/718.80
  6. Step 6: Final answer
    x = 839.79

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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.