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Finding the Fourth Proportional to 858.40, 1,183.78 and 623.90

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Solution

The fourth proportional to 858.40, 1,183.78 and 623.90 is: 860.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.40 : 1,183.78 = 623.90 : x
  2. Step 2: Convert to fraction form
    858.40/1,183.78 = 623.90/x
  3. Step 3: Cross multiply
    858.40x = 1,183.78 × 623.90
  4. Step 4: Simplify right side
    858.40x = 738,560.34
  5. Step 5: Solve for x
    x = 738,560.34/858.40
  6. Step 6: Final answer
    x = 860.39

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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.