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Finding the Fourth Proportional to 777.10, 1,070.40 and 636.70

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Solution

The fourth proportional to 777.10, 1,070.40 and 636.70 is: 877.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    777.10 : 1,070.40 = 636.70 : x
  2. Step 2: Convert to fraction form
    777.10/1,070.40 = 636.70/x
  3. Step 3: Cross multiply
    777.10x = 1,070.40 × 636.70
  4. Step 4: Simplify right side
    777.10x = 681,523.68
  5. Step 5: Solve for x
    x = 681,523.68/777.10
  6. Step 6: Final answer
    x = 877.01

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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.