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Finding the Fourth Proportional to 858.45, 1,287.37 and 281.19

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Solution

The fourth proportional to 858.45, 1,287.37 and 281.19 is: 421.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.45 : 1,287.37 = 281.19 : x
  2. Step 2: Convert to fraction form
    858.45/1,287.37 = 281.19/x
  3. Step 3: Cross multiply
    858.45x = 1,287.37 × 281.19
  4. Step 4: Simplify right side
    858.45x = 361,994.16
  5. Step 5: Solve for x
    x = 361,994.16/858.45
  6. Step 6: Final answer
    x = 421.68

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.