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Finding the Fourth Proportional to 777.45, 1,071.63 and 611.40

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Solution

The fourth proportional to 777.45, 1,071.63 and 611.40 is: 842.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    777.45 : 1,071.63 = 611.40 : x
  2. Step 2: Convert to fraction form
    777.45/1,071.63 = 611.40/x
  3. Step 3: Cross multiply
    777.45x = 1,071.63 × 611.40
  4. Step 4: Simplify right side
    777.45x = 655,194.58
  5. Step 5: Solve for x
    x = 655,194.58/777.45
  6. Step 6: Final answer
    x = 842.75

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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.