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Finding the Fourth Proportional to 858.41, 1,287.60 and 209.13

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Solution

The fourth proportional to 858.41, 1,287.60 and 209.13 is: 313.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.41 : 1,287.60 = 209.13 : x
  2. Step 2: Convert to fraction form
    858.41/1,287.60 = 209.13/x
  3. Step 3: Cross multiply
    858.41x = 1,287.60 × 209.13
  4. Step 4: Simplify right side
    858.41x = 269,275.79
  5. Step 5: Solve for x
    x = 269,275.79/858.41
  6. Step 6: Final answer
    x = 313.69

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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.