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Finding the Fourth Proportional to 777.60, 1,074.12 and 647.28

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Solution

The fourth proportional to 777.60, 1,074.12 and 647.28 is: 894.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    777.60 : 1,074.12 = 647.28 : x
  2. Step 2: Convert to fraction form
    777.60/1,074.12 = 647.28/x
  3. Step 3: Cross multiply
    777.60x = 1,074.12 × 647.28
  4. Step 4: Simplify right side
    777.60x = 695,256.39
  5. Step 5: Solve for x
    x = 695,256.39/777.60
  6. Step 6: Final answer
    x = 894.11

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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.