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Finding the Fourth Proportional to 858.19, 1,287.29 and 281.07

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Solution

The fourth proportional to 858.19, 1,287.29 and 281.07 is: 421.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.19 : 1,287.29 = 281.07 : x
  2. Step 2: Convert to fraction form
    858.19/1,287.29 = 281.07/x
  3. Step 3: Cross multiply
    858.19x = 1,287.29 × 281.07
  4. Step 4: Simplify right side
    858.19x = 361,818.60
  5. Step 5: Solve for x
    x = 361,818.60/858.19
  6. Step 6: Final answer
    x = 421.61

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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.