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Finding the Fourth Proportional to 778.56, 1,074.53 and 498.78

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Solution

The fourth proportional to 778.56, 1,074.53 and 498.78 is: 688.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.56 : 1,074.53 = 498.78 : x
  2. Step 2: Convert to fraction form
    778.56/1,074.53 = 498.78/x
  3. Step 3: Cross multiply
    778.56x = 1,074.53 × 498.78
  4. Step 4: Simplify right side
    778.56x = 535,948.70
  5. Step 5: Solve for x
    x = 535,948.70/778.56
  6. Step 6: Final answer
    x = 688.39

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1.5x scale

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.